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Construction waste estimation depending on urban planning options in the design stage of residential buildings
Construction and Building Materials 113 (2016) 561–570
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Construction waste estimation depending on urban planning options in the design stage of residential buildings Manuel Carpio a,⇑, Julio Roldán-Fontana b, Rosalía Pacheco-Torres b, Javier Ordóñez b a b
Institute of Civil Engineering, Faculty of Engineering Sciences, Austral University of Chile, Valdivia, Chile Department of Engineering Construction and Project Management, University of Granada, Spain
h i g h l i g h t s This study compares the environmental impact of different urban options. The objective is to evaluate environmental impact of urban planning. This study highlights the importance of an urban environmentally friendly design. Waste generated in the previous works on the lot should not be ignored.
a r t i c l e
i n f o
Article history: Received 11 February 2016 Received in revised form 11 March 2016 Accepted 15 March 2016
Keywords: Construction Demolition Waste Urban planning Efficiency Building Material
a b s t r a c t In the framework of the integral construction of urban residences and buildings is necessary a previous study to analyze the evaluation and management of waste generated throughout the building process. This key ingredient of urban planning responds, in part, to growing environmental problems and a more acute awareness of the consequences that improper management of such wastes would entail. A previous quantification of the waste generated through construction – during the project stage – is needed so that the best building proposal may be chosen. Urban planners and policy makers should develop a keen eye for selecting cost-effective projects while environmentally friendly. The aim of this paper is to study the production of waste in light of diverse urban solutions, both in the urban planning and building stages, as well as in global terms. To this end we studied six types of housing projects through simulations using statistical data, for different purposes, but with a common construction surface (50,000 m2): (i) detached single-family unit; (ii) semi-detached single-family unit; (iii) 5floor apartment block; (iv) 10-floor apartment block; (iv) 20-floor apartment block; and (vi) 40-floor apartment block. The main finding is that linear constructions generate a greater volume of waste than vertical construction, the difference reaching up to 57%. Ó 2016 Elsevier Ltd. All rights reserved.
1. Introduction Construction and Demolition Waste (CDW) represents over one-third of the total solid waste in the world [1]. Clearly, buildings present a high index of environmental impact throughout their life cycles, and the generation of CDW contributes substantially to this environmental impact. Many materials are involved in building construction, so that choosing adequate materials and systems during the design stage is essential to reduce the future environmental impact of buildings [2]. This calls for knowing, with precision, the volume and type of the waste generated throughout the useful life of the building.
⇑ Corresponding author. E-mail address: [email protected] (M. Carpio). http://dx.doi.org/10.1016/j.conbuildmat.2016.03.061 0950-0618/Ó 2016 Elsevier Ltd. All rights reserved.
Wu et al. [3] highlighted the important benefits to be obtained from the economic and environmental study of waste management and organization when construction is underway. The design and selection of adequate material are key factors for reducing the environmental impact of a building [4]. Adequate knowledge of the types of waste produced and their quantity, at a regional level, is an essential step for the promotion of more realistic policies as well as the implantation of recycling methods. The quantification and classification of waste from building construction can be approached at a macro or at a micro level. In their evaluation of the former, authors Cochran and Townsend [5] evaluated volumes of construction material and demolition waste in the US at a national level. Ding et al. [6] used statistical data at the national level to estimate the building and demolition waste generated in the region of Shanghai. At the micro level, previous work [7,8] has focused on analyzing a single building type.
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Although it is known that the specific building typology strongly conditions the type and amount of waste generated [9], little literature can be found in this respect. The typology and quantity of waste generated vary across the different phase of the buildings. In the phase of building construction, a greater volume of material and a vast proportion of the waste generated are associated with the movement of land. During the phase of residential building use, the volume of waste generated is more closely related with the tasks of maintenance, remodeling and reforms. In the demolition stage great amounts of waste are produced overall, yet especially if there are no recycling mechanisms involved [2]. Although the phase of use/occupation of buildings has the greatest environmental impact, it is also necessary to carry out studies that look into the rest of the stages [10]. A more detailed understanding should facilitate the implantation of mechanisms for a better management of waste, to ensure greater efficacy [11,12]. At the same time, this paper presents a classification and quantification of the waste generated during the stage of building for urban/residential purposes, establishing diverse urban planning scenarios, to compare results depending on the building type. The three most common residential building typologies are analyzed, and a total of 6 scenarios are evaluated [13–15]. For each scenario, the level of waste generated during the phase of construction was evaluated and a classification was carried out, considering as well the work of preparing the land for urban use. The results obtained, together with the findings of a previous related study on CO2 emissions for the same residential units under the same conditions [16], can be interpreted as a comprehensive evaluation of the environmental impact of the construction phase of different urban planning options. The aim of this paper is to study the production of waste in light of diverse urban solutions, both in the urban planning and building stages, as well as in global terms. To this end we studied six types of housing projects through simulations, for different purposes but with a common construction surface. Our study takes in the most representative building types of the residential sector in Spain. However, as non-standardized products, their properties depend on the design criteria applied in each project [4]. Instating measures for the reduction of environmental impact at the global level in a set of buildings in the design stage is no easy task. Notwithstanding, there is a dire need for the inclusion of urban planning criteria aimed for sustainable design and development. Integrating such measures in the design stage of a set of buildings—even if developed in the framework of different projects—may prove to be more efficient and cost-effective in the end analysis. 2. Material and methods In this section are described the urban solutions used; the description of construction systems and quantification of materials; and the normative on waste classification. 2.1. Urban solutions In this study, a hypothetical total surface allotment of 100,000 m2 has been considered for designing different urban solutions. The plot to be urbanized was circular, distributed into: Built area. The buildable rate considered is 0.5 m2/m2 (roof/floor). Therefore, a total of 50,000 m2 of land area would be occupied by residential buildings. Assigned spaces for public. According to the Spanish Rules for Development [17], a proportion of the urbanized plot must be devoted to public uses: school use, commercial use, social use and sport installations use. Summing up, public spaces represents the 12.87% of the plot area. Leisure space. The rest of the area is considered as free space. According to previous studies [16], the most representative typologies of the residential stock in Spain are studied: detached houses, semi-detached houses
and multi-familiar blocks. In the case of multi-familiar blocks, four block heights are considered: 5 floors height, 10 floors height, 20 floor height and 40 floor height. In the case of single-family houses, each house corresponds to one dwelling. In the case of multi-family units, the built area corresponds to a set of dwellings. The floor distribution is the same for all the multi-family cases, varying the number of floors. For all the cases, one parking space per dwelling was to be situated underground (the underground surface not counting as living space). The six urban designs studied are: URB-1. Residential development with detached single-family units (2 floors + tower). URB-2. Semi-detached single-family units (2 floors + tower). URB-3. Multi-family units, 8 blocks of 5-floor apt. buildings with one underground floor for parking. URB-4. Multi-family units, 4 blocks of 10-floor apt. buildings with two floors underground for parking. URB-5. Multi-family units, 2 blocks of 20-floor units, with four underground floors for parking. URB-6. Multi-family units, a block having 40 floors above ground and 8 underground floors for parking. Based on the initial premise that the above-ground built area was 50,000 m2, each design had a different number of buildings. Also, the distribution of roads, streets and free space varies from one urban solution to other. The land distribution and the differences between the different urban solutions are plotted in Fig. 1. Table 1 summarizes the building characteristics and urban features of the six urban options designed. More information on the design of the six urban solutions and the floor plans is given in a previous research [16]. Regarding normative purposes, the hypothetical plot of the study is located in the city of Granada (Spain), under application of the so-called Land Law [18] and the Technical Building Code (CTE) [19]. 2.2. Description of construction systems and quantification of materials Both the buildings as well as the civil infrastructures, were characterized with the most common construction techniques and materials in Spain. The buildings foundations were made of reinforced concrete slab. The structural framework was composed of columns and waffle slabs, also made of reinforced concrete. Double cavity brick walls, a traffic bearing roof as well as aluminum frame windows, compose the rest of the elements of the envelope. Indoor finishes are composed of ceramic flooring and cavity brick partitions walls with plaster and painting layers. Regarding the civil works, sidewalks are made of hydraulic flooring on mass concrete and gravel subbase. Both the kerbs and water lines on the sidewalks are composed of pieces of granite on a concrete base. The road network is composed by two layers of asphaltic concrete on a base of artificial gravel and natural gravel. Water supply system is composed of cast-iron pipe. In the case of sewage network, it is composed of concrete piping for diameters greater than or equal to 0.6 m and PVC piping for smaller diameters The gas supply network is solved with HDPE pipeline. The electricity grid, lighting network and telecommunications network is solved by a PVC piping of variable diameters according to the standard. The water supply system, sewage network and gas supply network were placed on a bed of sand, whereas electricity network, lighting and telecommunications were placed on a bed of concrete. The materials involved in foundation and structure (mainly concrete, cement and steel) are responsible of a great part of the environmental impact of housing construction [20–22]. In our study, the foundation and structure were calculated in accordance with the direct stiffness method. The output of this calculation was the description and quantity of those materials involved in these task, for each of the six case studied. In the stiffness method, the relation between the stresses and deformations of the bar elements was assumed to be linear with six degree of freedom per node. The relation between the stresses of each element and the displacement was based on the equation f = KD, where K is the stiffness matrix of the element, and D is the displacements of the nodes. This calculations were performed with the software program CYPECAD [23], under license by the University of Granada. All the necessaries task for the construction of the buildings and the development of civil infrastructures were grouped into construction work units, listed in Table 2. The materials involved in each task unit during the construction phase, were quantified. More information on the quantification and distribution of materials is given in a previous work [16]. The construction material quantification was the basis for the estimation of the waste generated in the construction phase. 2.3. Normative on waste classification Previous studies [24] regarding waste assessment on different stages of the building do not agree about the distribution of waste generated, especially with respect to the waste of lesser volume. Such classifications should, ideally, be undertaken with reference to the legislative framework of the European Union, specifically in view of the List of European Waste (LOW) [25].
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
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Fig. 1. Urban planning models.
In Spain, the Royal Decree 105/2008 [26] regulates the production and management of construction and demolition waste. This Royal Decree establishes the legal regimen for the production and management of waste produced through construction and demolition, in order to foment: (i) its prevention; (ii) re-utilization; (iii) recycling and other forms of acquiring value; (iv) ensuring that the waste intended for operations of elimination receives proper treatment to that end; and (v) to contribute to a sustainable development of construction activity. This applies to the waste from construction and demolition defined in Article 2 of the same document [26], and to that defined in Article 3 of Law 22/2011 [27], on waste and contaminated land, with the following exceptions: a) Land/soil and stone surfaces not contaminated by hazardous substances reutilized in the same construction work, in a different work, or in an activity of restoration, conditioning or refill, whenever their re-utilization can be properly accredited. b) Waste from extractive industries regulated by European Directive 2006/21/ EC [28]. c) Non-hazardous mud dredged and relocated in the interior of surface waters deriving from activities of water and navigable waterway management, for the prevention of flooding or mitigation of the effects of floods or droughts, regulated by Legislative Royal Decree 2/2011[29], by which the Refunded Text of the Law of Ports of the State and Merchant Marine is ratified, as well as the international treaties in which Spain takes part. Even though land/soil is considered a waste, under RD 105/2008 [26] the lands defined in section a) lie beyond the scope of application, whenever the conditions
described in this section prevail. The present study takes both options into account, considering land and stone as waste, under RD 105/2008. When establishing the classification of waste generated in the construction of residential buildings to this end, two significant considerations were the stage of construction underway, and waste identification in light of the LOW. For each material, it was estimated the waste generated in the following stages: the raw material supply; transport form the site of extraction; manufacture; transport to the building site; construction/emplacement in situ. According to Commission Decision 2000/532/EC [25], the LOW is meant to be a reference nomenclature providing a common terminology throughout the European Community, intended to improve the efficiency of waste management activities. The LOW serves as a common encoding of waste characteristics for a broad variety of purposes, such as the classification of hazardous wastes. Assignment of waste codes has a major impact on the transport of waste, installation permits (usually granted for the processing of specific waste codes), decisions about the recyclability of waste, or as a basis for waste statistics. The LOW is divided into twenty chapters, most of them industry-based, but some are based on materials and processes. Each has a two-digit chapter code, from 01 to 20. Each chapter has one or more subchapters, identified by four digit codes (the first two digits constituting the chapter code). Within these sub-chapters there are more specific codes for individual waste streams, for instance, which is assigned a six-digit code. Table 3 lists the wastes identified in the present study, for the section on building, identified by their codes and description, as well as the classification within their respective chapters and subchapters. With reference to urban development, fewer wastes were identified, all of them likewise classified under building. Table 3 shows the wastes present in both sections.
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Table 1 Housing profile characteristics and urban planning characteristics. Planning of the sector. Land division categories
Semi-Detached (URB-2)
5-floor building (URB-3)
10-fl. apt. building (URB-4)
20-fl. apt. Building (URB-5)
40-fl. apt. Building (URB-6)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Useful land Residential land basic unit Block 1 Block 2 Block 3 Block 4 Block 5 Block 6 Block 7 Block 8 Block 9 Block 10 Block 11 Block 12 Block 13 Total residential land use
3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 4,100.54 51,534.94
14 23 15 14 23 15 14 23 15 14 23 15 17 225
3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 4,100.54 51,534.94
20 30 25 20 30 25 20 30 25 20 30 25 25 325
10,104.5 10,104.5 10,104.5 10,104.5
120 120 120 120
10,104.5 10,104.5 10,104.5 10,104.5
120 120 120 120
21,077.2 21,077.2
240 240
43,022.61
480
40,418.00
480
40,418.00
480
42,154.40
480
43,022.61
480
Public land conceded Road system Allotted land Land allotment for commercial use Land allotted for social use Land allotted for school use Land allotted for sports installations Total land allotted Leisure space Total land use for leisure areas Total land reserved for allotments
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 10,000.37 10,000.37 22,874.05
Road system Parking placesa Road Total land use for the road network Ceded public land Total land designated for building
25,591.01 25,591.01 47,313.96 100,000.00
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 10,000.37 10,000.37 22,874.05 164
Number of parking places according to Spanish normative.
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 164
25,591.01 25,591.01 47,313.96
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 385
15,655.76 15,655.76 58,430.90
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 385
15,655.76 15,655.76 58,430.90
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 433
13,919.36 13,919.36 56,694.50
427 13,051.15 13,051.15 55,826.29
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
a
Detached (URB-1) Surface (m2)
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570 Table 2 Task units for building construction and civil and infrastructural works. Buildings Construction i ii iii iv v vi vii
Civil and infrastructural works i ii iii iv v vi vii
Land preparation Earth moving Water supply network Sewage network Medium voltage network Public Lighting Telecommunications network
viii ix x
Land preparation Foundations Frame structures Façades Envelopes and partitions walls Installations Thermic and acoustic insulation and waterproofing Roofing Wallcoverings or Siding Signs and Equipment
viii ix x
xi
Urbanization
xi
xii
Waste management
xii
xiii xiv
Quality control and testing Health and safety
xiii
Gas network Paving Landscaping and treatment of green areas Irrigation and water supply / watering network Urban furniture or street furniture Road markings or signs
3. Results The results obtained are divided into two groupings. The first considers land excavation as a waste, whereas the second does not. In both, the distinction between building and urban development is made. 3.1. Considering land excavation 3.1.1. Waste generated by building With the results obtained for building waste, Table 4 shows that the optimal building type is URB-5, corresponding to two buildings with 20 floors. These are global results, taking as a criterion the type with the least weight of waste. According to Li et al. [30], for a comparison of the amount of waste generated between different construction projects, is more feasible to compare the waste weight instead of the volume, because of the variations of the density of mixed waste. Following URB-5, in order, would be URB-6, with a very similar percentage, and then URB-4, URB-3, URB-1 and, finally, URB-2. According to these results, it can be said in general that the more extensive the building type, the greater the volume of building waste is generated. The least favorable case would be 300% more ‘‘wasteful” than the most favorable type. In Table 5, all the waste types generated in building are grouped into 5 categories, corresponding to chapters 01, 08, 15, 17 and 20, although practically all (99%) correspond to chapter 17, relative to construction and demolition. The waste classified as code 17 05 04 (land and stone) are the most abundant, amounting to 93% for unit type URB-5, and 97% for type URB-2, of the total weight of waste. This grouping corresponds to the movement of land necessary for the construction, meaning that a less extensive building type implies less land movement; hence the detached single-family unit and the semi-detached ones will present higher percentages. For all the building types, the hazardous waste deriving from building construction consistently revealed the prevalence of two types: paint and varnish containing organic solvents or other dangerous substances (code 08 01 11); and containers having the remains of hazardous substances or contact with them (code 15 01 10). Both categories are a minor constituent of the total (0.09%). Notwithstanding, their hazardous nature calls for the separate careful study and treatment of such substances. Regarding paint waste, all the apartment buildings studied (URB-3 to URB-6) gave virtually the same amount, some 10 tons (0.01%). The single family units gave diverse results: the detached
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homes (URB-1) gave 11 tons, whereas the semi-detached ones (URB-2) produced only 4 tons. This marked difference can be attributed to the surface requiring painting, as more than half of the exterior wall coverings of the semi-detached homes are partitioning walls. Contaminated containers are responsible for a greater percentage of hazardous waste than the remains of paint, and they contribute 0.08% of the total for the optimal building type. There are no major differences in this category, the least contaminating building type being URB-6, with 64 tons, as opposed to URB-1 and URB-3, each with 79 tons. When taking both waste categories into account, the worst results (more hazardous waste) are found for URB-1. As seen in Table 5, with reference to the waste from prospection of the first group (code 01 04 08), gravel and rock waste, there is a noteworthy increase of the order of 1500% in the 40-floor block (397 t) with respect to the detached homes (23 t), and this is inversely proportional to the volumes of category 01 04 09; indeed, sand and clay waste increases by 1140% in the single-standing singlefamily units with respect to block 40. These results are logical given that a more extensive (longitudinal) construction requires less excavation depth; in comparison, the tall building needs a deep foundation in addition to the parking garages, meaning that the surface materials will be of a clay-related nature. 3.1.2. Waste generated in urban development For urban development, just as for building construction, adopting the total weight of waste as the criterion, the optimal unit type proved to be URB-6, the 40-floor block. In contrast, the one generating the most waste was URB-1. In fact, the detached home generated 210.83% more waste than URB-6. Types URB-5, URB-4, URB-3 and URB-2 progressively produced more waste, from 106.16%, to 129.27%, 137.01% and 178.62% more, respectively. Table 6 shows all the waste products broken down into five major groupings. These are: 01. Waste of prospection, extraction from mines and quarries and physical and chemical treatment of minerals; 15. Waste of containers; absorbent ones, cleaning cloths, filtration materials, and protective clothing not specified in another category; 17. Waste from construction and demolition (including land excavated from contaminated zones); and 20. Municipal waste (domestic waste and degradable waste from commerce, industry and institutions), including the fractions collected selectively. The percentage that each waste represents against the whole, for each class, is similar for all six cases. Likewise, whether for urban development or building construction, for the optimal solution land/soil (17 05 04) amounts to over 98% of the waste generated. The second most substantial waste generated in these works are the ones deriving from road/street-cleaning (248 t), followed by cement (code 17 01 01; 158 t), sand and clays (01 04 09; 89 t), wooden containers (15 01 03; 62 t), tiles and ceramic materials (17 01 03; 57 t). Respectively, they represent 0.64%, 0.41%, 0.23%, 0.16% and 0.15% of the total. The remainder of the waste generated by urban development is below 0.1%. However, deserving mention here is the case of hazardous waste, as only containers with the remains of dangerous substances (15 01 10) constitute a problem, with 0.01 t. 3.2. Without excavated land As seen in the previous section, land/soil and stone (17 05 04) represent most of the waste from both building construction and civil engineering works. Below we analyze the results excluding from the scope of application soil and stones, in accordance with RD 105/2008 [26], as long as the conditions stipulated are fulfilled.
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M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
Table 3 Wastes from the LOW list affected in this study. LOW code
Waste
01 01 04 01 04 08
WASTES RESULTING FROM EXPLORATION, MINING, QUARRYING, AND PHYSICAL AND CHEMICAL TREATMENT OF MINERALS Wastes from physical and chemical processing of non-metalliferous minerals Waste gravel and crushed rocks other than those mentioned in 01 04 07 (*wastes containing hazardous substances from physical and chemical processing of non-metalliferous minerals) Waste sand and clays Wastes from stone cutting and sawing other than those mentioned in 01 04 07 (*wastes containing hazardous substances from physical and chemical processing of non-metalliferous minerals) WASTES FROM THE MANUFACTURE, FORMULATION, SUPPLY AND USE (MFSU) OF COATINGS (PAINTS, VARNISHES AND VITREOUS ENAMELS), ADHESIVES, SEALANTS AND PRINTING INKS Wastes from MFSU and removal of paint and varnish * Waste paint and varnish containing organic solvents or other hazardous substances WASTE PACKAGING; ABSORBENTS, WIPING CLOTHS, FILTER MATERIALS AND PROTECTIVE CLOTHING NOT OTHERWISE SPECIFIED Packaging (including separately collected municipal packaging waste) Paper and cardboard packaging Plastic packaging Wooden packaging Metallic packaging Packaging containing waste of or contaminated by hazardous substances CONSTRUCTION AND DEMOLITION WASTES (INCLUDING EXCAVATED SOIL FROM CONTAMINATED SITES) Concrete, bricks, tiles and ceramics Concrete Bricks Tiles and ceramics Mixtures of concrete, bricks, tiles and ceramics other than those mentioned in 17 01 06 (*mixtures of, or separate fractions of concrete, bricks, tiles and ceramics containing hazardous substances) Wood, glass and plastic Wood Glass Plastic Bituminous mixtures, coal tar and tarred products Bituminous mixtures other than those mentioned in 17 03 01 Metals (including their alloys) Copper, bronze, brass Aluminum Iron and steel Cables other than those mentioned in 17 04 10 (*cables containing oil, coal tar and other hazardous substances) Soil (including excavated soil from contaminated sites) Soil and stones other than those mentioned in 17 05 03 (*soil and stones containing hazardous substances) Insulation materials and asbestos-containing construction materials Insulation materials other than those mentioned in 17 06 01(*insulation materials containing asbestos)and 17 06 03 (*other insulation materials consisting of or containing hazardous substances) Gypsum-based construction material Gypsum-based construction materials other than those mentioned in 17 08 01(*gypsum-based construction materials contaminated with hazardous substances) Other construction and demolition wastes Mixed construction and demolition wastes other than those mentioned in 17 09 01 (*construction and demolition wastes containing mercury), 17 09 02 (*construction and demolition wastes containing PCB (for example PCB-containing sealants, PCB-containing resinbased floorings, PCB-containing sealed glazing units, PCB-containing capacitors) and 17 09 03(*other construction and demolition wastes (including mixed wastes) containing hazardous substances) MUNICIPAL WASTES (HOUSEHOLD WASTE AND SIMILAR COMMERCIAL, INDUSTRIAL AND INSTITUTIONAL WASTES) INCLUDING SEPARATELY COLLECTED FRACTIONS Other municipal wastes Street-cleaning waste
01 04 09 01 04 13 08 08 08 15 15 15 15 15 15 15 17 17 17 17 17 17
01 01 11*
17 17 17 17 17 17 17 17 17 17 17 17 17 17 17
02 02 02 02 03 03 04 04 04 04 04 05 05 06 06
01 01 01 01 01 01
01 02 03 04 10*
01 01 01 01 01
01 02 03 07
01 02 03 02 01 02 05 11 04 04
17 08 17 08 02 17 09 17 09 04
20 20 03 20 03 03 *
Build.
Urb.
X
X
X X
X
X
X X X X X
X X X X X
X X X X
X X X X
X X X
X X X
X X X X X
X X
X
X
X
X
X
X
X
X
X
Hazardous Build..: Concerning Building; Urb.:Concerning urbanization.
Table 4 Total wastes for the housing development profiles.
Housing profile Number of buildings Building surface (m2) Waste (t/m2)
URB-1
URB-2
URB-3
URB-4
URB-5
URB-6
Detached 225 307 3.47
Semi-detached 65 1,144 4.19
Block 5 8 7,592 2.01
Block 10 4 15,185 1.82
Block 20 2 30,369 1.72
Block 40 1 60,739 1.71
159,710.18 102.37% 13,808.58 110.83% 173,518.76 102.39%
198,702.69 151.78% 10,564.89 109.19% 209,267.58 144.09%
92,400.81 17.08% 8,221.99 39.75% 100,622.80 17.37%
83,161.86 5.38% 7,646.11 14.40% 90,807.97 5.92%
78,918.84 0.00% 6,870.65 6.93% 85,789.49 0.07%
79,818.84 0.41% 5,914.77 0.00% 85,733.61 0.00%
With 17 05 04 Building construction wastes (t) % in regards to the optimum Civil engineering works (t) % in regards to the optimum Total construction wastes (t) % in regards to the optimum
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M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570 Table 5 Building waste. LOW code
01 Wastes from treatment of minerals
08 Waste from MFSU
15 Waste packaging
17 Construction and demolition wastes
20 Municipal wastes
Total
URB-1
198,202 (0.12%) 122,969 (0.06%) 202,630 (0.22%) 258,080 (0.31%) 402,421 (0.51%) 397,440 (0.50%)
11,328 (0.01%) 3,943 (0.01%) 9,745 (0.01%) 9,700 (0.01%) 10,074 (0.01%) 9,667 (0.01%)
78,861 (0.05%) 67,541 (0.03%) 79,248 (0.09%) 69,750 (0.08%) 66,113 (0.08%) 64,373 (0.08%)
158,587,896 (99.30%) 198,067,963 (99.68%) 91,925,702 (99.49%) 82,732,589 (99.48%) 78,394,364 (99.34%) 78,746,045 (99.38%)
833,893 (0.52%) 440,274 (0.22%) 183,488 (0.20%) 91,744 (0.11%) 45,872 (0.06%) 22,936 (0.03%)
159,710,180 (100%) 198,702,691 (100%) 92,400,813 (100%) 83,161,863 (100%) 78,918,844 (100%) 79,240,460 (100%)
URB-2 URB-3 URB-4 URB-5 URB-6
Measurement in tons; For more information see Table 3.
Table 6 Civil engineering work waste. LOW code
01 Wastes from treatment of minerals
15 Waste packaging
17 Construction and demolition wastes
20 Municipal wastes
Total
URB-1
278,569 (0.34%) 298,273 (0.37%) 110,011 (0.20%) 103,280 (0.23%) 92,726 (0.22%) 90,078 (0.23%)
236,324 (0.29%) 235,580 (0.29%) 140,558 (0.26%) 72,572 (0.16%) 63,051 (0.15%) 62,681 (0.16%)
80,741,801 (98.82%) 80,087,744 (98.79%) 53,615,003 (99.00%) 43,866,434 (98.94%) 40,990,377 (98.92%) 38,353,878 (98.97%)
450,096 (0.55%) 450,096 (0.56%) 293,190 (0.54%) 293,190 (0.66%) 293,190 (0.71%) 247,625 (0.64%)
81,706,791 (100%) 81,071,693 (100%) 54,158,763 (100%) 44,335,476 (100%) 41,439,345 (100%) 38,754,262 (100%)
URB-2 URB-3 URB-4 URB-5 URB-6
Measurement in tons; For more information see Table 3.
The waste generated, quantitatively, is the same as defined for the section considering land as a waste; but the percentages will differ. As can be seen in Table 7, the optimal type of residential unit with regard to building waste is type URB-3 (5-floor apartment block), followed by URB-4, URB-6 and URB-5 at a slight distance, with types URB-2 and URB-1 showing substantial increases of 24.35% and 54.05%, respectively. When focusing on the waste from civil engineering works, Table 7 reveals the optimal structure to be URB-6 (40-floor construction), followed by URB-5, URB-4, URB-3, URB-2 and, finally URB-1. This progression suggests that the greater extension of the construction implies a greater amount of waste from urban development. There is an increase of 103.70% associated with the detached single-family units as compared to the 40-floor block. Overall, the sum of waste generated by building construction and civil works shows that the best solution is URB-4 (Table 7), corresponding to the 10-floor block. Yet similar percentages are obtained for URB-6, URB-3 and URB-5. In contrast, URB-2 obtains a value of 31.85%, and the least favorable is URB-1, with 57.08%. On the one hand, the waste produced by building residential units is found to be ‘‘optimal” in global terms, for URB-4, or block 10; and as seen in Fig. 2, there are various waste components that constitute most of the global value. More than half correspond to bricks (17 01 02) (32%) and concrete (17 01 01) (27%), followed by chalk-based construction materials (17 08 02) (11%), and mixtures of concrete, brick, tiles and ceramic materials (17 01 07) (9%). These wastes stand as 4/5 of the total. The remaining 1/5 can be broken down into lesser percentages, as illustrated in Fig. 2. In the context of civil works, however, the waste generated is far different. This is reflected in Fig. 3. Approximately 4/5 of the waste comes from road/street-cleaning (20 03 03) (40%), mostly
due to previous land clearing, followed by concrete (17 01 01) (23%), sand and clay waste (01 04 09) (14%), wooden containers (15 01 03) (10%), and tiles and ceramic materials (17 01 03) (8%). The rest (1/5) would be divided up as indicated in the sub-graph of Fig. 3. 4. Discussion The results of our study make manifest the importance of considering (or not) the volume of land excavated when calculating waste and its subsequent environmental impact, since quite different conclusions can be drawn. This is true for residential buildings as well as for the developments, as clearly observed in Tables 4 and 7. In the stage of construction, and when land is excluded from analysis, the most favorable option is URB-3, substantially better than the other tall buildings (URB-4, URB-5, and URB-6). Nevertheless, when land is included in the equation, the volume of waste generated is greater for low, linear buildings. This owes to the fact that more buildings are needed to cover the total built surface; consequently, the volume of land extracted is greater. In the case of developments, the best results are observed for URB-6, regardless of whether land is considered or not. This would be because this option calls for fewer roadways, hence less surrounding pavement. The global balance thus highlights one or another option as the best, in terms of the volume of waste generated, depending on whether land/soil was considered. This is an important point, to be stressed here and addressed later on. The data obtained and exposed in this study clearly indicated that the single-family units—detached or not—are the option gen-
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Table 7 Total wastes for the housing development profiles. Without 17 05 04 – Soil and stones other than those mentioned in 17 05 03 (See Table 3).
Housing profile Number of buildings Building surface (m2) Waste (t/m2) Without 17 05 04 Building construction wastes (t) % in regards to the optimum Civil engineering works (t) % in regards to the optimum Total construction wastes (t) % in regards to the optimum
URB-1
URB-2
URB-3
URB-4
URB-5
URB-6
Detached 225 307 0.18
Semi-detached 65 1,144 0.15
Block 5 8 7,592 0.11
Block 10 4 15,185 0.11
Block 20 2 30,369 0.12
Block 40 1 60,739 0.11
7,588.89 54.05% 1,330.07 103.70% 8,918.96 57.08%
6,125.89 24.35% 1,360.39 108.35% 7,486.29 31.85%
4,926.34 0.00% 811.79 24.33% 5,738.13 1.06%
4,941.24 0.30% 736.75 12.83% 5,677.99 0.00%
5,282.33 7.23% 708.47 8.50% 5,990.79 5.51%
5,071.66 2.95% 652.95 0.00% 5,724.61 0.82%
Fig. 2. % Building construction waste.
erating more waste overall (up to 144% more when land/soil is included as a criterion). Considering results reported elsewhere [22], in which the CO2 emissions deriving from the stage of construction of single-family homes were shown to be higher than those from block apartment buildings, it can be said that singlefamily units are associated with a greater environmental impact during their Life Cycle. The results obtained in other studies showed that the CO2 emissions of residential buildings can be reduced by 95% respectively when constructive solutions with low U-values and renewable energy are implemented [31,32]. Moreover the climatic zone is an important factor in the calculation of CO2 emissions factor [33]. The findings put forth here demonstrate that an estimation of the waste generated in the construction stage of buildings includes that deriving from the development of the lot, and the optimal building option is not the same as when such developmental aspects are not considered. Moreover, our results show that the residential unit generating the least amount of waste (discounting urban development) is the unit designated as URB-3 when land is excluded from the equation, and URB-5 when land is included. In turn, when the global evaluation takes in the waste deriving from development, the most beneficial option would be either URB-4 (excluding land) or URB-6 (including consideration of land).
The developmental work on a lot for residential use, with a building and the type and volume of waste generated, are an intrinsic part of the need to give the building proper conditions for dwelling, so that the building will fulfill the function for which it was meant. The results of our study demonstrate that the volume of waste produced during the developmental stage depends largely on the urban plan chosen, and has substantial impact on the total waste figures: anywhere between 8% with land, and 18% without land. Therefore, the Life Cycle of a building should take into account the work invested in developing the surrounding area. Although a number of previous studies quantify the waste generated in the stage of building of residential buildings in Spain, they tend to be carried out at the micro scale (a single building), or else a macro scale (a region or entire country) but without making distinctions among building typologies. Our research analyzes the different types of residential units, while also including developmental work in the global calculations. In any of the possible evaluation scenarios, it is confirmed that the options entailing single-family units (whether detached or not) mean a greater volume of waste, both for construction and for development. The very definition of such residential units is associated with a high consumption of material and land allotment per m2 built. Moreover, urban planning surrounding these options calls
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
569
Fig. 3. % Civil engineering waste.
for an extensive network of utility supply, and a comparatively vast surface of pavement. In turn, buildings of a vertical nature allow for living surfaces requiring a reduced quantity of construction materials, and therefore show a more cost-effective approach in the use of materials. Likewise, by being more centralized, the networks of electric and water supply are shorter in length, and the paved surface of the residential development is reduced. Determining the option with the least environmental impact will depend on the inclusion or omission of land as a criterion of consideration. This is a very significant finding. Insofar as the classification of waste, our results are distorted when land is considered. When excluding land, the most abundant waste overall in the building stage would consist of bricks and cement. During development, the predominant waste products are cement and waste from street cleaning. These findings are in line with the results reported by Llatas [1], Cochram [5] and Solís-Guzmán [34]. This article underlines the need to evaluate, globally, the environmental impact of a vast proportion of land, instead of evaluating many different building options individually. The volume of the work and type of development can be viewed as a consequence of the construction types planned to occupy a lot; in other words, building design should be carried out in conjunction with development, not separately. As is shown here, considering the waste from lot development can be a very important difference when deciding on an optimal structural unit from the standpoint of waste reduction. It is therefore logical that the study of waste produced and the Life Cycle Analysis of a building and a development be undertaken in coordinated fashion. 5. Conclusions This study compares building options based on diverse urban solutions for the respective lots, but with the same total surface, and common criteria for building, design and development. The study features a novel approach, proposing that the evaluation of waste generated in the building stage should include not only the materials directly related with construction, but also those generated in the preparation and the developmental work surrounding the lot where it is situated.
Considering soil (17 05 04) as a building waste, the most favorable residential solution is URB-5, while in terms of development it would be URB-6. In global terms, the most favorable is URB-6, followed closely by URB-5 (increase of 0.07%); in contrast, the least favorable are URB-2 and URB-1, their respective waste being 144% and 103% greater than the optimal solution. When land/soil is not considered to constitute waste, the most favorable building solution corresponds to URB-3, and the best developmental option is URB-6. In global terms, the optimal solution is URB-4, followed in order by URB-6, URB-3 and URB-5, with increases between 1% and 6%. The least favorable solutions are the single-family units, URB-1 and URB-2, entailing respective increases of 57 and 32%. The waste generated during the stage of land movement is most significant in the stage of building for all the urban options, amounting to 93–97% of the total. Therefore, it would be advantageous to treat it according to the specifications of RD 105/2008, so that it would cease to be considered as waste. Furthermore, these findings make manifest the potential reduction of environmental impact through re-utilization of the land excavated during the building stage. These results may be extrapolated and applied to planning processes involving urban developments; or might even be used to more precisely define essential building properties. They will hopefully prove useful, in the future, in the context of decisionmaking or policy-creation by the competent authorities or agents.
References [1] C. Llatas, A model for quantifying construction waste in projects according to the European waste list, Waste Manag. 31 (6) (2011) 1261–1276. [2] K. Condeixa, A. Haddad, D. Boer, Life cycle impact assessment of masonry system as inner walls: a case study in Brazil, Constr. Build. Mater. 70 (2014) 141–147. [3] Z. Wu, A.T.W. Yu, L. Shen, G. Liu, Quantifying construction and demolition waste: an analytical review, Waste Manag. 34 (9) (2014) 1683–1692. [4] M.M. Khasreen, P.F.G. Banfill, G.F. Menzies, Life-cycle assessment and the environmental impact of buildings: a review, Sustainability 1 (3) (2009) 674– 701. [5] K.M. Cochran, T.G. Townsend, Estimating construction and demolition debris generation using a materials flow analysis approach, Waste Manag. 30 (11) (2010) 2247–2254. [6] T. Ding, J. Xiao, Estimation of building-related construction and demolition waste in Shanghai, Waste Manag. 34 (11) (2014) 2327–2334.
570
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
[7] P. Mercader-Moyano, A. Ramírez-de-Arellano-Agudo, Selective classification and quantification model of C&D waste from material resources consumed in residential building construction, Waste Manag. Res. 31 (5) (2013) 458–474. [8] S.K. Lachimpadi, J.J. Pereira, M.R. Taha, M. Mokhtar, Construction waste minimisation comparing conventional and precast construction (Mixed System and IBS) methods in high-rise buildings: a Malaysia case study, Resour. Conserv. Recycl. 68 (2012) 96–103. [9] A. Coelho, J. de Brito, Distribution of materials in construction and demolition waste in Portugal, Waste Manag. Res. 29 (8) (2011) 843–853. [10] T. Ramesh, R. Prakash, K.K. Shukla, Life cycle energy analysis of a residential building with different envelopes and climates in Indian context, Appl. Energy 89 (1) (2012) 193–202. [11] O. Ortiz, C. Bonnet, J.C. Bruno, F. Castells, Sustainability based on LCM of residential dwellings: a case study in Catalonia, Spain, Build. Environ. 44 (3) (2009) 584–594. [12] O. Ortiz, J.C. Pasqualino, F. Castells, Environmental performance of construction waste: Comparing three scenarios from a case study in Catalonia, Spain, Waste Manag. 30 (4) (2010) 646–654. [13] Instituto Nacional de Estadística [Online], Available:. [14] Consejo Superior de Colegios de Arquitectos de España [Online], Available: . [15] Consejo General de la Arquitectura Técnica de España [Online], Available:
[22] R. Pacheco-Torres, E. Jadraque, J. Roldán-Fontana, J. Ordóñez, Analysis of CO2 emissions in the construction phase of single-family detached houses, Sustainable Cities Soc. 12 (2014) 63–68. [23] CYPE Ingenieros S.A., CYPE 2014, 2014. [24] A. Coelho, J. de Brito, Environmental analysis of a construction and demolition waste recycling plant in Portugal-Part I: energy consumption and CO2 emissions, Waste Manag. 33 (5) (2013) 1258–1267. [25] European Parliament and of the Council, Decision 2000/532/EC on the list of waste pursuant to Directive 2008/98/EC of the European Parliament and of the Council (Text with EEA relevance). [26] Government of Spain, Real Decreto 105/2008, de 1 de febrero, por el que se regula la producción y gestión de los residuos de construcción y demolición, 2008. [27] Government of Spain, Ley 22/2011, de 28 de julio, de residuos y suelos contaminados, 2011. [28] Council of the European Communities, Directiva 2006/21/CE del Parlamento Europeo y del Consejo, de 15 de marzo de 2006, sobre la gestión de los residuos de industrias extractivas y por la que se modifica la Directiva 2004/ 35/CE, 2006. [29] G. of S. Ministerio de Fomento, Real Decreto Legislativo 2/2011, de 5 de septiembre, por el que se aprueba el Texto Refundido de la Ley de Puertos del Estado y de la Marina Mercante, 2011. [30] J. Li, Z. Ding, X. Mi, J. Wang, A model for estimating construction waste generation index for building project in China, Resour. Conserv. Recycl. 74 (2013) 20–26. [31] M. Carpio, A. García-Maraver, D.P. Ruiz, M. Martín-Morales, Impact of the envelope design of residential buildings on their acclimation energy demand, CO2 emissions and energy rating, WIT Trans. Ecol. Environ. 186 (2014) 387–398. [32] M. Carpio, M. Zamorano, M. Costa, Impact of using biomass boilers on the energy rating and CO2 emissions of Iberian Peninsula residential buildings, Energy Build. 66 (2013) 732–744. [33] M. Carpio, J. Jódar, M.L. Rodíguez, M. Zamorano, A proposed method based on approximation and interpolation for determining climatic zones and its effect on energy demand and CO2 emissions from buildings, Energy Build. 87 (2015) 253–264. [34] J. Solís-Guzmán, M. Marrero, M.V. Montes-Delgado, A. Ramírez-de-Arellano, A Spanish model for quantification and management of construction waste, Waste Manag. 29 (9) (2009) 2542–2548.
Contents lists available at ScienceDirect
Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat
Construction waste estimation depending on urban planning options in the design stage of residential buildings Manuel Carpio a,⇑, Julio Roldán-Fontana b, Rosalía Pacheco-Torres b, Javier Ordóñez b a b
Institute of Civil Engineering, Faculty of Engineering Sciences, Austral University of Chile, Valdivia, Chile Department of Engineering Construction and Project Management, University of Granada, Spain
h i g h l i g h t s This study compares the environmental impact of different urban options. The objective is to evaluate environmental impact of urban planning. This study highlights the importance of an urban environmentally friendly design. Waste generated in the previous works on the lot should not be ignored.
a r t i c l e
i n f o
Article history: Received 11 February 2016 Received in revised form 11 March 2016 Accepted 15 March 2016
Keywords: Construction Demolition Waste Urban planning Efficiency Building Material
a b s t r a c t In the framework of the integral construction of urban residences and buildings is necessary a previous study to analyze the evaluation and management of waste generated throughout the building process. This key ingredient of urban planning responds, in part, to growing environmental problems and a more acute awareness of the consequences that improper management of such wastes would entail. A previous quantification of the waste generated through construction – during the project stage – is needed so that the best building proposal may be chosen. Urban planners and policy makers should develop a keen eye for selecting cost-effective projects while environmentally friendly. The aim of this paper is to study the production of waste in light of diverse urban solutions, both in the urban planning and building stages, as well as in global terms. To this end we studied six types of housing projects through simulations using statistical data, for different purposes, but with a common construction surface (50,000 m2): (i) detached single-family unit; (ii) semi-detached single-family unit; (iii) 5floor apartment block; (iv) 10-floor apartment block; (iv) 20-floor apartment block; and (vi) 40-floor apartment block. The main finding is that linear constructions generate a greater volume of waste than vertical construction, the difference reaching up to 57%. Ó 2016 Elsevier Ltd. All rights reserved.
1. Introduction Construction and Demolition Waste (CDW) represents over one-third of the total solid waste in the world [1]. Clearly, buildings present a high index of environmental impact throughout their life cycles, and the generation of CDW contributes substantially to this environmental impact. Many materials are involved in building construction, so that choosing adequate materials and systems during the design stage is essential to reduce the future environmental impact of buildings [2]. This calls for knowing, with precision, the volume and type of the waste generated throughout the useful life of the building.
⇑ Corresponding author. E-mail address: [email protected] (M. Carpio). http://dx.doi.org/10.1016/j.conbuildmat.2016.03.061 0950-0618/Ó 2016 Elsevier Ltd. All rights reserved.
Wu et al. [3] highlighted the important benefits to be obtained from the economic and environmental study of waste management and organization when construction is underway. The design and selection of adequate material are key factors for reducing the environmental impact of a building [4]. Adequate knowledge of the types of waste produced and their quantity, at a regional level, is an essential step for the promotion of more realistic policies as well as the implantation of recycling methods. The quantification and classification of waste from building construction can be approached at a macro or at a micro level. In their evaluation of the former, authors Cochran and Townsend [5] evaluated volumes of construction material and demolition waste in the US at a national level. Ding et al. [6] used statistical data at the national level to estimate the building and demolition waste generated in the region of Shanghai. At the micro level, previous work [7,8] has focused on analyzing a single building type.
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Although it is known that the specific building typology strongly conditions the type and amount of waste generated [9], little literature can be found in this respect. The typology and quantity of waste generated vary across the different phase of the buildings. In the phase of building construction, a greater volume of material and a vast proportion of the waste generated are associated with the movement of land. During the phase of residential building use, the volume of waste generated is more closely related with the tasks of maintenance, remodeling and reforms. In the demolition stage great amounts of waste are produced overall, yet especially if there are no recycling mechanisms involved [2]. Although the phase of use/occupation of buildings has the greatest environmental impact, it is also necessary to carry out studies that look into the rest of the stages [10]. A more detailed understanding should facilitate the implantation of mechanisms for a better management of waste, to ensure greater efficacy [11,12]. At the same time, this paper presents a classification and quantification of the waste generated during the stage of building for urban/residential purposes, establishing diverse urban planning scenarios, to compare results depending on the building type. The three most common residential building typologies are analyzed, and a total of 6 scenarios are evaluated [13–15]. For each scenario, the level of waste generated during the phase of construction was evaluated and a classification was carried out, considering as well the work of preparing the land for urban use. The results obtained, together with the findings of a previous related study on CO2 emissions for the same residential units under the same conditions [16], can be interpreted as a comprehensive evaluation of the environmental impact of the construction phase of different urban planning options. The aim of this paper is to study the production of waste in light of diverse urban solutions, both in the urban planning and building stages, as well as in global terms. To this end we studied six types of housing projects through simulations, for different purposes but with a common construction surface. Our study takes in the most representative building types of the residential sector in Spain. However, as non-standardized products, their properties depend on the design criteria applied in each project [4]. Instating measures for the reduction of environmental impact at the global level in a set of buildings in the design stage is no easy task. Notwithstanding, there is a dire need for the inclusion of urban planning criteria aimed for sustainable design and development. Integrating such measures in the design stage of a set of buildings—even if developed in the framework of different projects—may prove to be more efficient and cost-effective in the end analysis. 2. Material and methods In this section are described the urban solutions used; the description of construction systems and quantification of materials; and the normative on waste classification. 2.1. Urban solutions In this study, a hypothetical total surface allotment of 100,000 m2 has been considered for designing different urban solutions. The plot to be urbanized was circular, distributed into: Built area. The buildable rate considered is 0.5 m2/m2 (roof/floor). Therefore, a total of 50,000 m2 of land area would be occupied by residential buildings. Assigned spaces for public. According to the Spanish Rules for Development [17], a proportion of the urbanized plot must be devoted to public uses: school use, commercial use, social use and sport installations use. Summing up, public spaces represents the 12.87% of the plot area. Leisure space. The rest of the area is considered as free space. According to previous studies [16], the most representative typologies of the residential stock in Spain are studied: detached houses, semi-detached houses
and multi-familiar blocks. In the case of multi-familiar blocks, four block heights are considered: 5 floors height, 10 floors height, 20 floor height and 40 floor height. In the case of single-family houses, each house corresponds to one dwelling. In the case of multi-family units, the built area corresponds to a set of dwellings. The floor distribution is the same for all the multi-family cases, varying the number of floors. For all the cases, one parking space per dwelling was to be situated underground (the underground surface not counting as living space). The six urban designs studied are: URB-1. Residential development with detached single-family units (2 floors + tower). URB-2. Semi-detached single-family units (2 floors + tower). URB-3. Multi-family units, 8 blocks of 5-floor apt. buildings with one underground floor for parking. URB-4. Multi-family units, 4 blocks of 10-floor apt. buildings with two floors underground for parking. URB-5. Multi-family units, 2 blocks of 20-floor units, with four underground floors for parking. URB-6. Multi-family units, a block having 40 floors above ground and 8 underground floors for parking. Based on the initial premise that the above-ground built area was 50,000 m2, each design had a different number of buildings. Also, the distribution of roads, streets and free space varies from one urban solution to other. The land distribution and the differences between the different urban solutions are plotted in Fig. 1. Table 1 summarizes the building characteristics and urban features of the six urban options designed. More information on the design of the six urban solutions and the floor plans is given in a previous research [16]. Regarding normative purposes, the hypothetical plot of the study is located in the city of Granada (Spain), under application of the so-called Land Law [18] and the Technical Building Code (CTE) [19]. 2.2. Description of construction systems and quantification of materials Both the buildings as well as the civil infrastructures, were characterized with the most common construction techniques and materials in Spain. The buildings foundations were made of reinforced concrete slab. The structural framework was composed of columns and waffle slabs, also made of reinforced concrete. Double cavity brick walls, a traffic bearing roof as well as aluminum frame windows, compose the rest of the elements of the envelope. Indoor finishes are composed of ceramic flooring and cavity brick partitions walls with plaster and painting layers. Regarding the civil works, sidewalks are made of hydraulic flooring on mass concrete and gravel subbase. Both the kerbs and water lines on the sidewalks are composed of pieces of granite on a concrete base. The road network is composed by two layers of asphaltic concrete on a base of artificial gravel and natural gravel. Water supply system is composed of cast-iron pipe. In the case of sewage network, it is composed of concrete piping for diameters greater than or equal to 0.6 m and PVC piping for smaller diameters The gas supply network is solved with HDPE pipeline. The electricity grid, lighting network and telecommunications network is solved by a PVC piping of variable diameters according to the standard. The water supply system, sewage network and gas supply network were placed on a bed of sand, whereas electricity network, lighting and telecommunications were placed on a bed of concrete. The materials involved in foundation and structure (mainly concrete, cement and steel) are responsible of a great part of the environmental impact of housing construction [20–22]. In our study, the foundation and structure were calculated in accordance with the direct stiffness method. The output of this calculation was the description and quantity of those materials involved in these task, for each of the six case studied. In the stiffness method, the relation between the stresses and deformations of the bar elements was assumed to be linear with six degree of freedom per node. The relation between the stresses of each element and the displacement was based on the equation f = KD, where K is the stiffness matrix of the element, and D is the displacements of the nodes. This calculations were performed with the software program CYPECAD [23], under license by the University of Granada. All the necessaries task for the construction of the buildings and the development of civil infrastructures were grouped into construction work units, listed in Table 2. The materials involved in each task unit during the construction phase, were quantified. More information on the quantification and distribution of materials is given in a previous work [16]. The construction material quantification was the basis for the estimation of the waste generated in the construction phase. 2.3. Normative on waste classification Previous studies [24] regarding waste assessment on different stages of the building do not agree about the distribution of waste generated, especially with respect to the waste of lesser volume. Such classifications should, ideally, be undertaken with reference to the legislative framework of the European Union, specifically in view of the List of European Waste (LOW) [25].
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Fig. 1. Urban planning models.
In Spain, the Royal Decree 105/2008 [26] regulates the production and management of construction and demolition waste. This Royal Decree establishes the legal regimen for the production and management of waste produced through construction and demolition, in order to foment: (i) its prevention; (ii) re-utilization; (iii) recycling and other forms of acquiring value; (iv) ensuring that the waste intended for operations of elimination receives proper treatment to that end; and (v) to contribute to a sustainable development of construction activity. This applies to the waste from construction and demolition defined in Article 2 of the same document [26], and to that defined in Article 3 of Law 22/2011 [27], on waste and contaminated land, with the following exceptions: a) Land/soil and stone surfaces not contaminated by hazardous substances reutilized in the same construction work, in a different work, or in an activity of restoration, conditioning or refill, whenever their re-utilization can be properly accredited. b) Waste from extractive industries regulated by European Directive 2006/21/ EC [28]. c) Non-hazardous mud dredged and relocated in the interior of surface waters deriving from activities of water and navigable waterway management, for the prevention of flooding or mitigation of the effects of floods or droughts, regulated by Legislative Royal Decree 2/2011[29], by which the Refunded Text of the Law of Ports of the State and Merchant Marine is ratified, as well as the international treaties in which Spain takes part. Even though land/soil is considered a waste, under RD 105/2008 [26] the lands defined in section a) lie beyond the scope of application, whenever the conditions
described in this section prevail. The present study takes both options into account, considering land and stone as waste, under RD 105/2008. When establishing the classification of waste generated in the construction of residential buildings to this end, two significant considerations were the stage of construction underway, and waste identification in light of the LOW. For each material, it was estimated the waste generated in the following stages: the raw material supply; transport form the site of extraction; manufacture; transport to the building site; construction/emplacement in situ. According to Commission Decision 2000/532/EC [25], the LOW is meant to be a reference nomenclature providing a common terminology throughout the European Community, intended to improve the efficiency of waste management activities. The LOW serves as a common encoding of waste characteristics for a broad variety of purposes, such as the classification of hazardous wastes. Assignment of waste codes has a major impact on the transport of waste, installation permits (usually granted for the processing of specific waste codes), decisions about the recyclability of waste, or as a basis for waste statistics. The LOW is divided into twenty chapters, most of them industry-based, but some are based on materials and processes. Each has a two-digit chapter code, from 01 to 20. Each chapter has one or more subchapters, identified by four digit codes (the first two digits constituting the chapter code). Within these sub-chapters there are more specific codes for individual waste streams, for instance, which is assigned a six-digit code. Table 3 lists the wastes identified in the present study, for the section on building, identified by their codes and description, as well as the classification within their respective chapters and subchapters. With reference to urban development, fewer wastes were identified, all of them likewise classified under building. Table 3 shows the wastes present in both sections.
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Table 1 Housing profile characteristics and urban planning characteristics. Planning of the sector. Land division categories
Semi-Detached (URB-2)
5-floor building (URB-3)
10-fl. apt. building (URB-4)
20-fl. apt. Building (URB-5)
40-fl. apt. Building (URB-6)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Surface (m2)
No. of dwellings
Useful land Residential land basic unit Block 1 Block 2 Block 3 Block 4 Block 5 Block 6 Block 7 Block 8 Block 9 Block 10 Block 11 Block 12 Block 13 Total residential land use
3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 4,100.54 51,534.94
14 23 15 14 23 15 14 23 15 14 23 15 17 225
3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 3,231.08 5,219.85 3,407.67 4,100.54 51,534.94
20 30 25 20 30 25 20 30 25 20 30 25 25 325
10,104.5 10,104.5 10,104.5 10,104.5
120 120 120 120
10,104.5 10,104.5 10,104.5 10,104.5
120 120 120 120
21,077.2 21,077.2
240 240
43,022.61
480
40,418.00
480
40,418.00
480
42,154.40
480
43,022.61
480
Public land conceded Road system Allotted land Land allotment for commercial use Land allotted for social use Land allotted for school use Land allotted for sports installations Total land allotted Leisure space Total land use for leisure areas Total land reserved for allotments
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 10,000.37 10,000.37 22,874.05
Road system Parking placesa Road Total land use for the road network Ceded public land Total land designated for building
25,591.01 25,591.01 47,313.96 100,000.00
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 10,000.37 10,000.37 22,874.05 164
Number of parking places according to Spanish normative.
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 164
25,591.01 25,591.01 47,313.96
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 385
15,655.76 15,655.76 58,430.90
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 385
15,655.76 15,655.76 58,430.90
1,151.10 1,511.13 6,043.59 4,167.86 12,873.68 31,052.56 31,052.56 43,926.24 433
13,919.36 13,919.36 56,694.50
427 13,051.15 13,051.15 55,826.29
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
a
Detached (URB-1) Surface (m2)
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570 Table 2 Task units for building construction and civil and infrastructural works. Buildings Construction i ii iii iv v vi vii
Civil and infrastructural works i ii iii iv v vi vii
Land preparation Earth moving Water supply network Sewage network Medium voltage network Public Lighting Telecommunications network
viii ix x
Land preparation Foundations Frame structures Façades Envelopes and partitions walls Installations Thermic and acoustic insulation and waterproofing Roofing Wallcoverings or Siding Signs and Equipment
viii ix x
xi
Urbanization
xi
xii
Waste management
xii
xiii xiv
Quality control and testing Health and safety
xiii
Gas network Paving Landscaping and treatment of green areas Irrigation and water supply / watering network Urban furniture or street furniture Road markings or signs
3. Results The results obtained are divided into two groupings. The first considers land excavation as a waste, whereas the second does not. In both, the distinction between building and urban development is made. 3.1. Considering land excavation 3.1.1. Waste generated by building With the results obtained for building waste, Table 4 shows that the optimal building type is URB-5, corresponding to two buildings with 20 floors. These are global results, taking as a criterion the type with the least weight of waste. According to Li et al. [30], for a comparison of the amount of waste generated between different construction projects, is more feasible to compare the waste weight instead of the volume, because of the variations of the density of mixed waste. Following URB-5, in order, would be URB-6, with a very similar percentage, and then URB-4, URB-3, URB-1 and, finally, URB-2. According to these results, it can be said in general that the more extensive the building type, the greater the volume of building waste is generated. The least favorable case would be 300% more ‘‘wasteful” than the most favorable type. In Table 5, all the waste types generated in building are grouped into 5 categories, corresponding to chapters 01, 08, 15, 17 and 20, although practically all (99%) correspond to chapter 17, relative to construction and demolition. The waste classified as code 17 05 04 (land and stone) are the most abundant, amounting to 93% for unit type URB-5, and 97% for type URB-2, of the total weight of waste. This grouping corresponds to the movement of land necessary for the construction, meaning that a less extensive building type implies less land movement; hence the detached single-family unit and the semi-detached ones will present higher percentages. For all the building types, the hazardous waste deriving from building construction consistently revealed the prevalence of two types: paint and varnish containing organic solvents or other dangerous substances (code 08 01 11); and containers having the remains of hazardous substances or contact with them (code 15 01 10). Both categories are a minor constituent of the total (0.09%). Notwithstanding, their hazardous nature calls for the separate careful study and treatment of such substances. Regarding paint waste, all the apartment buildings studied (URB-3 to URB-6) gave virtually the same amount, some 10 tons (0.01%). The single family units gave diverse results: the detached
565
homes (URB-1) gave 11 tons, whereas the semi-detached ones (URB-2) produced only 4 tons. This marked difference can be attributed to the surface requiring painting, as more than half of the exterior wall coverings of the semi-detached homes are partitioning walls. Contaminated containers are responsible for a greater percentage of hazardous waste than the remains of paint, and they contribute 0.08% of the total for the optimal building type. There are no major differences in this category, the least contaminating building type being URB-6, with 64 tons, as opposed to URB-1 and URB-3, each with 79 tons. When taking both waste categories into account, the worst results (more hazardous waste) are found for URB-1. As seen in Table 5, with reference to the waste from prospection of the first group (code 01 04 08), gravel and rock waste, there is a noteworthy increase of the order of 1500% in the 40-floor block (397 t) with respect to the detached homes (23 t), and this is inversely proportional to the volumes of category 01 04 09; indeed, sand and clay waste increases by 1140% in the single-standing singlefamily units with respect to block 40. These results are logical given that a more extensive (longitudinal) construction requires less excavation depth; in comparison, the tall building needs a deep foundation in addition to the parking garages, meaning that the surface materials will be of a clay-related nature. 3.1.2. Waste generated in urban development For urban development, just as for building construction, adopting the total weight of waste as the criterion, the optimal unit type proved to be URB-6, the 40-floor block. In contrast, the one generating the most waste was URB-1. In fact, the detached home generated 210.83% more waste than URB-6. Types URB-5, URB-4, URB-3 and URB-2 progressively produced more waste, from 106.16%, to 129.27%, 137.01% and 178.62% more, respectively. Table 6 shows all the waste products broken down into five major groupings. These are: 01. Waste of prospection, extraction from mines and quarries and physical and chemical treatment of minerals; 15. Waste of containers; absorbent ones, cleaning cloths, filtration materials, and protective clothing not specified in another category; 17. Waste from construction and demolition (including land excavated from contaminated zones); and 20. Municipal waste (domestic waste and degradable waste from commerce, industry and institutions), including the fractions collected selectively. The percentage that each waste represents against the whole, for each class, is similar for all six cases. Likewise, whether for urban development or building construction, for the optimal solution land/soil (17 05 04) amounts to over 98% of the waste generated. The second most substantial waste generated in these works are the ones deriving from road/street-cleaning (248 t), followed by cement (code 17 01 01; 158 t), sand and clays (01 04 09; 89 t), wooden containers (15 01 03; 62 t), tiles and ceramic materials (17 01 03; 57 t). Respectively, they represent 0.64%, 0.41%, 0.23%, 0.16% and 0.15% of the total. The remainder of the waste generated by urban development is below 0.1%. However, deserving mention here is the case of hazardous waste, as only containers with the remains of dangerous substances (15 01 10) constitute a problem, with 0.01 t. 3.2. Without excavated land As seen in the previous section, land/soil and stone (17 05 04) represent most of the waste from both building construction and civil engineering works. Below we analyze the results excluding from the scope of application soil and stones, in accordance with RD 105/2008 [26], as long as the conditions stipulated are fulfilled.
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Table 3 Wastes from the LOW list affected in this study. LOW code
Waste
01 01 04 01 04 08
WASTES RESULTING FROM EXPLORATION, MINING, QUARRYING, AND PHYSICAL AND CHEMICAL TREATMENT OF MINERALS Wastes from physical and chemical processing of non-metalliferous minerals Waste gravel and crushed rocks other than those mentioned in 01 04 07 (*wastes containing hazardous substances from physical and chemical processing of non-metalliferous minerals) Waste sand and clays Wastes from stone cutting and sawing other than those mentioned in 01 04 07 (*wastes containing hazardous substances from physical and chemical processing of non-metalliferous minerals) WASTES FROM THE MANUFACTURE, FORMULATION, SUPPLY AND USE (MFSU) OF COATINGS (PAINTS, VARNISHES AND VITREOUS ENAMELS), ADHESIVES, SEALANTS AND PRINTING INKS Wastes from MFSU and removal of paint and varnish * Waste paint and varnish containing organic solvents or other hazardous substances WASTE PACKAGING; ABSORBENTS, WIPING CLOTHS, FILTER MATERIALS AND PROTECTIVE CLOTHING NOT OTHERWISE SPECIFIED Packaging (including separately collected municipal packaging waste) Paper and cardboard packaging Plastic packaging Wooden packaging Metallic packaging Packaging containing waste of or contaminated by hazardous substances CONSTRUCTION AND DEMOLITION WASTES (INCLUDING EXCAVATED SOIL FROM CONTAMINATED SITES) Concrete, bricks, tiles and ceramics Concrete Bricks Tiles and ceramics Mixtures of concrete, bricks, tiles and ceramics other than those mentioned in 17 01 06 (*mixtures of, or separate fractions of concrete, bricks, tiles and ceramics containing hazardous substances) Wood, glass and plastic Wood Glass Plastic Bituminous mixtures, coal tar and tarred products Bituminous mixtures other than those mentioned in 17 03 01 Metals (including their alloys) Copper, bronze, brass Aluminum Iron and steel Cables other than those mentioned in 17 04 10 (*cables containing oil, coal tar and other hazardous substances) Soil (including excavated soil from contaminated sites) Soil and stones other than those mentioned in 17 05 03 (*soil and stones containing hazardous substances) Insulation materials and asbestos-containing construction materials Insulation materials other than those mentioned in 17 06 01(*insulation materials containing asbestos)and 17 06 03 (*other insulation materials consisting of or containing hazardous substances) Gypsum-based construction material Gypsum-based construction materials other than those mentioned in 17 08 01(*gypsum-based construction materials contaminated with hazardous substances) Other construction and demolition wastes Mixed construction and demolition wastes other than those mentioned in 17 09 01 (*construction and demolition wastes containing mercury), 17 09 02 (*construction and demolition wastes containing PCB (for example PCB-containing sealants, PCB-containing resinbased floorings, PCB-containing sealed glazing units, PCB-containing capacitors) and 17 09 03(*other construction and demolition wastes (including mixed wastes) containing hazardous substances) MUNICIPAL WASTES (HOUSEHOLD WASTE AND SIMILAR COMMERCIAL, INDUSTRIAL AND INSTITUTIONAL WASTES) INCLUDING SEPARATELY COLLECTED FRACTIONS Other municipal wastes Street-cleaning waste
01 04 09 01 04 13 08 08 08 15 15 15 15 15 15 15 17 17 17 17 17 17
01 01 11*
17 17 17 17 17 17 17 17 17 17 17 17 17 17 17
02 02 02 02 03 03 04 04 04 04 04 05 05 06 06
01 01 01 01 01 01
01 02 03 04 10*
01 01 01 01 01
01 02 03 07
01 02 03 02 01 02 05 11 04 04
17 08 17 08 02 17 09 17 09 04
20 20 03 20 03 03 *
Build.
Urb.
X
X
X X
X
X
X X X X X
X X X X X
X X X X
X X X X
X X X
X X X
X X X X X
X X
X
X
X
X
X
X
X
X
X
Hazardous Build..: Concerning Building; Urb.:Concerning urbanization.
Table 4 Total wastes for the housing development profiles.
Housing profile Number of buildings Building surface (m2) Waste (t/m2)
URB-1
URB-2
URB-3
URB-4
URB-5
URB-6
Detached 225 307 3.47
Semi-detached 65 1,144 4.19
Block 5 8 7,592 2.01
Block 10 4 15,185 1.82
Block 20 2 30,369 1.72
Block 40 1 60,739 1.71
159,710.18 102.37% 13,808.58 110.83% 173,518.76 102.39%
198,702.69 151.78% 10,564.89 109.19% 209,267.58 144.09%
92,400.81 17.08% 8,221.99 39.75% 100,622.80 17.37%
83,161.86 5.38% 7,646.11 14.40% 90,807.97 5.92%
78,918.84 0.00% 6,870.65 6.93% 85,789.49 0.07%
79,818.84 0.41% 5,914.77 0.00% 85,733.61 0.00%
With 17 05 04 Building construction wastes (t) % in regards to the optimum Civil engineering works (t) % in regards to the optimum Total construction wastes (t) % in regards to the optimum
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M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570 Table 5 Building waste. LOW code
01 Wastes from treatment of minerals
08 Waste from MFSU
15 Waste packaging
17 Construction and demolition wastes
20 Municipal wastes
Total
URB-1
198,202 (0.12%) 122,969 (0.06%) 202,630 (0.22%) 258,080 (0.31%) 402,421 (0.51%) 397,440 (0.50%)
11,328 (0.01%) 3,943 (0.01%) 9,745 (0.01%) 9,700 (0.01%) 10,074 (0.01%) 9,667 (0.01%)
78,861 (0.05%) 67,541 (0.03%) 79,248 (0.09%) 69,750 (0.08%) 66,113 (0.08%) 64,373 (0.08%)
158,587,896 (99.30%) 198,067,963 (99.68%) 91,925,702 (99.49%) 82,732,589 (99.48%) 78,394,364 (99.34%) 78,746,045 (99.38%)
833,893 (0.52%) 440,274 (0.22%) 183,488 (0.20%) 91,744 (0.11%) 45,872 (0.06%) 22,936 (0.03%)
159,710,180 (100%) 198,702,691 (100%) 92,400,813 (100%) 83,161,863 (100%) 78,918,844 (100%) 79,240,460 (100%)
URB-2 URB-3 URB-4 URB-5 URB-6
Measurement in tons; For more information see Table 3.
Table 6 Civil engineering work waste. LOW code
01 Wastes from treatment of minerals
15 Waste packaging
17 Construction and demolition wastes
20 Municipal wastes
Total
URB-1
278,569 (0.34%) 298,273 (0.37%) 110,011 (0.20%) 103,280 (0.23%) 92,726 (0.22%) 90,078 (0.23%)
236,324 (0.29%) 235,580 (0.29%) 140,558 (0.26%) 72,572 (0.16%) 63,051 (0.15%) 62,681 (0.16%)
80,741,801 (98.82%) 80,087,744 (98.79%) 53,615,003 (99.00%) 43,866,434 (98.94%) 40,990,377 (98.92%) 38,353,878 (98.97%)
450,096 (0.55%) 450,096 (0.56%) 293,190 (0.54%) 293,190 (0.66%) 293,190 (0.71%) 247,625 (0.64%)
81,706,791 (100%) 81,071,693 (100%) 54,158,763 (100%) 44,335,476 (100%) 41,439,345 (100%) 38,754,262 (100%)
URB-2 URB-3 URB-4 URB-5 URB-6
Measurement in tons; For more information see Table 3.
The waste generated, quantitatively, is the same as defined for the section considering land as a waste; but the percentages will differ. As can be seen in Table 7, the optimal type of residential unit with regard to building waste is type URB-3 (5-floor apartment block), followed by URB-4, URB-6 and URB-5 at a slight distance, with types URB-2 and URB-1 showing substantial increases of 24.35% and 54.05%, respectively. When focusing on the waste from civil engineering works, Table 7 reveals the optimal structure to be URB-6 (40-floor construction), followed by URB-5, URB-4, URB-3, URB-2 and, finally URB-1. This progression suggests that the greater extension of the construction implies a greater amount of waste from urban development. There is an increase of 103.70% associated with the detached single-family units as compared to the 40-floor block. Overall, the sum of waste generated by building construction and civil works shows that the best solution is URB-4 (Table 7), corresponding to the 10-floor block. Yet similar percentages are obtained for URB-6, URB-3 and URB-5. In contrast, URB-2 obtains a value of 31.85%, and the least favorable is URB-1, with 57.08%. On the one hand, the waste produced by building residential units is found to be ‘‘optimal” in global terms, for URB-4, or block 10; and as seen in Fig. 2, there are various waste components that constitute most of the global value. More than half correspond to bricks (17 01 02) (32%) and concrete (17 01 01) (27%), followed by chalk-based construction materials (17 08 02) (11%), and mixtures of concrete, brick, tiles and ceramic materials (17 01 07) (9%). These wastes stand as 4/5 of the total. The remaining 1/5 can be broken down into lesser percentages, as illustrated in Fig. 2. In the context of civil works, however, the waste generated is far different. This is reflected in Fig. 3. Approximately 4/5 of the waste comes from road/street-cleaning (20 03 03) (40%), mostly
due to previous land clearing, followed by concrete (17 01 01) (23%), sand and clay waste (01 04 09) (14%), wooden containers (15 01 03) (10%), and tiles and ceramic materials (17 01 03) (8%). The rest (1/5) would be divided up as indicated in the sub-graph of Fig. 3. 4. Discussion The results of our study make manifest the importance of considering (or not) the volume of land excavated when calculating waste and its subsequent environmental impact, since quite different conclusions can be drawn. This is true for residential buildings as well as for the developments, as clearly observed in Tables 4 and 7. In the stage of construction, and when land is excluded from analysis, the most favorable option is URB-3, substantially better than the other tall buildings (URB-4, URB-5, and URB-6). Nevertheless, when land is included in the equation, the volume of waste generated is greater for low, linear buildings. This owes to the fact that more buildings are needed to cover the total built surface; consequently, the volume of land extracted is greater. In the case of developments, the best results are observed for URB-6, regardless of whether land is considered or not. This would be because this option calls for fewer roadways, hence less surrounding pavement. The global balance thus highlights one or another option as the best, in terms of the volume of waste generated, depending on whether land/soil was considered. This is an important point, to be stressed here and addressed later on. The data obtained and exposed in this study clearly indicated that the single-family units—detached or not—are the option gen-
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Table 7 Total wastes for the housing development profiles. Without 17 05 04 – Soil and stones other than those mentioned in 17 05 03 (See Table 3).
Housing profile Number of buildings Building surface (m2) Waste (t/m2) Without 17 05 04 Building construction wastes (t) % in regards to the optimum Civil engineering works (t) % in regards to the optimum Total construction wastes (t) % in regards to the optimum
URB-1
URB-2
URB-3
URB-4
URB-5
URB-6
Detached 225 307 0.18
Semi-detached 65 1,144 0.15
Block 5 8 7,592 0.11
Block 10 4 15,185 0.11
Block 20 2 30,369 0.12
Block 40 1 60,739 0.11
7,588.89 54.05% 1,330.07 103.70% 8,918.96 57.08%
6,125.89 24.35% 1,360.39 108.35% 7,486.29 31.85%
4,926.34 0.00% 811.79 24.33% 5,738.13 1.06%
4,941.24 0.30% 736.75 12.83% 5,677.99 0.00%
5,282.33 7.23% 708.47 8.50% 5,990.79 5.51%
5,071.66 2.95% 652.95 0.00% 5,724.61 0.82%
Fig. 2. % Building construction waste.
erating more waste overall (up to 144% more when land/soil is included as a criterion). Considering results reported elsewhere [22], in which the CO2 emissions deriving from the stage of construction of single-family homes were shown to be higher than those from block apartment buildings, it can be said that singlefamily units are associated with a greater environmental impact during their Life Cycle. The results obtained in other studies showed that the CO2 emissions of residential buildings can be reduced by 95% respectively when constructive solutions with low U-values and renewable energy are implemented [31,32]. Moreover the climatic zone is an important factor in the calculation of CO2 emissions factor [33]. The findings put forth here demonstrate that an estimation of the waste generated in the construction stage of buildings includes that deriving from the development of the lot, and the optimal building option is not the same as when such developmental aspects are not considered. Moreover, our results show that the residential unit generating the least amount of waste (discounting urban development) is the unit designated as URB-3 when land is excluded from the equation, and URB-5 when land is included. In turn, when the global evaluation takes in the waste deriving from development, the most beneficial option would be either URB-4 (excluding land) or URB-6 (including consideration of land).
The developmental work on a lot for residential use, with a building and the type and volume of waste generated, are an intrinsic part of the need to give the building proper conditions for dwelling, so that the building will fulfill the function for which it was meant. The results of our study demonstrate that the volume of waste produced during the developmental stage depends largely on the urban plan chosen, and has substantial impact on the total waste figures: anywhere between 8% with land, and 18% without land. Therefore, the Life Cycle of a building should take into account the work invested in developing the surrounding area. Although a number of previous studies quantify the waste generated in the stage of building of residential buildings in Spain, they tend to be carried out at the micro scale (a single building), or else a macro scale (a region or entire country) but without making distinctions among building typologies. Our research analyzes the different types of residential units, while also including developmental work in the global calculations. In any of the possible evaluation scenarios, it is confirmed that the options entailing single-family units (whether detached or not) mean a greater volume of waste, both for construction and for development. The very definition of such residential units is associated with a high consumption of material and land allotment per m2 built. Moreover, urban planning surrounding these options calls
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569
Fig. 3. % Civil engineering waste.
for an extensive network of utility supply, and a comparatively vast surface of pavement. In turn, buildings of a vertical nature allow for living surfaces requiring a reduced quantity of construction materials, and therefore show a more cost-effective approach in the use of materials. Likewise, by being more centralized, the networks of electric and water supply are shorter in length, and the paved surface of the residential development is reduced. Determining the option with the least environmental impact will depend on the inclusion or omission of land as a criterion of consideration. This is a very significant finding. Insofar as the classification of waste, our results are distorted when land is considered. When excluding land, the most abundant waste overall in the building stage would consist of bricks and cement. During development, the predominant waste products are cement and waste from street cleaning. These findings are in line with the results reported by Llatas [1], Cochram [5] and Solís-Guzmán [34]. This article underlines the need to evaluate, globally, the environmental impact of a vast proportion of land, instead of evaluating many different building options individually. The volume of the work and type of development can be viewed as a consequence of the construction types planned to occupy a lot; in other words, building design should be carried out in conjunction with development, not separately. As is shown here, considering the waste from lot development can be a very important difference when deciding on an optimal structural unit from the standpoint of waste reduction. It is therefore logical that the study of waste produced and the Life Cycle Analysis of a building and a development be undertaken in coordinated fashion. 5. Conclusions This study compares building options based on diverse urban solutions for the respective lots, but with the same total surface, and common criteria for building, design and development. The study features a novel approach, proposing that the evaluation of waste generated in the building stage should include not only the materials directly related with construction, but also those generated in the preparation and the developmental work surrounding the lot where it is situated.
Considering soil (17 05 04) as a building waste, the most favorable residential solution is URB-5, while in terms of development it would be URB-6. In global terms, the most favorable is URB-6, followed closely by URB-5 (increase of 0.07%); in contrast, the least favorable are URB-2 and URB-1, their respective waste being 144% and 103% greater than the optimal solution. When land/soil is not considered to constitute waste, the most favorable building solution corresponds to URB-3, and the best developmental option is URB-6. In global terms, the optimal solution is URB-4, followed in order by URB-6, URB-3 and URB-5, with increases between 1% and 6%. The least favorable solutions are the single-family units, URB-1 and URB-2, entailing respective increases of 57 and 32%. The waste generated during the stage of land movement is most significant in the stage of building for all the urban options, amounting to 93–97% of the total. Therefore, it would be advantageous to treat it according to the specifications of RD 105/2008, so that it would cease to be considered as waste. Furthermore, these findings make manifest the potential reduction of environmental impact through re-utilization of the land excavated during the building stage. These results may be extrapolated and applied to planning processes involving urban developments; or might even be used to more precisely define essential building properties. They will hopefully prove useful, in the future, in the context of decisionmaking or policy-creation by the competent authorities or agents.
References [1] C. Llatas, A model for quantifying construction waste in projects according to the European waste list, Waste Manag. 31 (6) (2011) 1261–1276. [2] K. Condeixa, A. Haddad, D. Boer, Life cycle impact assessment of masonry system as inner walls: a case study in Brazil, Constr. Build. Mater. 70 (2014) 141–147. [3] Z. Wu, A.T.W. Yu, L. Shen, G. Liu, Quantifying construction and demolition waste: an analytical review, Waste Manag. 34 (9) (2014) 1683–1692. [4] M.M. Khasreen, P.F.G. Banfill, G.F. Menzies, Life-cycle assessment and the environmental impact of buildings: a review, Sustainability 1 (3) (2009) 674– 701. [5] K.M. Cochran, T.G. Townsend, Estimating construction and demolition debris generation using a materials flow analysis approach, Waste Manag. 30 (11) (2010) 2247–2254. [6] T. Ding, J. Xiao, Estimation of building-related construction and demolition waste in Shanghai, Waste Manag. 34 (11) (2014) 2327–2334.
570
M. Carpio et al. / Construction and Building Materials 113 (2016) 561–570
[7] P. Mercader-Moyano, A. Ramírez-de-Arellano-Agudo, Selective classification and quantification model of C&D waste from material resources consumed in residential building construction, Waste Manag. Res. 31 (5) (2013) 458–474. [8] S.K. Lachimpadi, J.J. Pereira, M.R. Taha, M. Mokhtar, Construction waste minimisation comparing conventional and precast construction (Mixed System and IBS) methods in high-rise buildings: a Malaysia case study, Resour. Conserv. Recycl. 68 (2012) 96–103. [9] A. Coelho, J. de Brito, Distribution of materials in construction and demolition waste in Portugal, Waste Manag. Res. 29 (8) (2011) 843–853. [10] T. Ramesh, R. Prakash, K.K. Shukla, Life cycle energy analysis of a residential building with different envelopes and climates in Indian context, Appl. Energy 89 (1) (2012) 193–202. [11] O. Ortiz, C. Bonnet, J.C. Bruno, F. Castells, Sustainability based on LCM of residential dwellings: a case study in Catalonia, Spain, Build. Environ. 44 (3) (2009) 584–594. [12] O. Ortiz, J.C. Pasqualino, F. Castells, Environmental performance of construction waste: Comparing three scenarios from a case study in Catalonia, Spain, Waste Manag. 30 (4) (2010) 646–654. [13] Instituto Nacional de Estadística [Online], Available:
[22] R. Pacheco-Torres, E. Jadraque, J. Roldán-Fontana, J. Ordóñez, Analysis of CO2 emissions in the construction phase of single-family detached houses, Sustainable Cities Soc. 12 (2014) 63–68. [23] CYPE Ingenieros S.A., CYPE 2014, 2014. [24] A. Coelho, J. de Brito, Environmental analysis of a construction and demolition waste recycling plant in Portugal-Part I: energy consumption and CO2 emissions, Waste Manag. 33 (5) (2013) 1258–1267. [25] European Parliament and of the Council, Decision 2000/532/EC on the list of waste pursuant to Directive 2008/98/EC of the European Parliament and of the Council (Text with EEA relevance). [26] Government of Spain, Real Decreto 105/2008, de 1 de febrero, por el que se regula la producción y gestión de los residuos de construcción y demolición, 2008. [27] Government of Spain, Ley 22/2011, de 28 de julio, de residuos y suelos contaminados, 2011. [28] Council of the European Communities, Directiva 2006/21/CE del Parlamento Europeo y del Consejo, de 15 de marzo de 2006, sobre la gestión de los residuos de industrias extractivas y por la que se modifica la Directiva 2004/ 35/CE, 2006. [29] G. of S. Ministerio de Fomento, Real Decreto Legislativo 2/2011, de 5 de septiembre, por el que se aprueba el Texto Refundido de la Ley de Puertos del Estado y de la Marina Mercante, 2011. [30] J. Li, Z. Ding, X. Mi, J. Wang, A model for estimating construction waste generation index for building project in China, Resour. Conserv. Recycl. 74 (2013) 20–26. [31] M. Carpio, A. García-Maraver, D.P. Ruiz, M. Martín-Morales, Impact of the envelope design of residential buildings on their acclimation energy demand, CO2 emissions and energy rating, WIT Trans. Ecol. Environ. 186 (2014) 387–398. [32] M. Carpio, M. Zamorano, M. Costa, Impact of using biomass boilers on the energy rating and CO2 emissions of Iberian Peninsula residential buildings, Energy Build. 66 (2013) 732–744. [33] M. Carpio, J. Jódar, M.L. Rodíguez, M. Zamorano, A proposed method based on approximation and interpolation for determining climatic zones and its effect on energy demand and CO2 emissions from buildings, Energy Build. 87 (2015) 253–264. [34] J. Solís-Guzmán, M. Marrero, M.V. Montes-Delgado, A. Ramírez-de-Arellano, A Spanish model for quantification and management of construction waste, Waste Manag. 29 (9) (2009) 2542–2548.