Mix design charts for lightweight cellular cemented Bangkok clay

Applied Clay Science 104 (2015) 318–323

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Mix design charts for lightweight cellular cemented Bangkok clay Chairat Teerawattanasuk a, Panich Voottipruex b, Suksun Horpibulsuk c,⁎ a b c

Department of Civil and Environmental Engineering Technology, College of Industrial Technology, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand Department of Teacher Training in Civil Engineering, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand School of Civil Engineering, Center of Excellence in Civil Engineering, Suranaree University of Technology, 111 University Avenue, Muang District, Nakhon Ratchasima 30000, Thailand

a r t i c l e

i n f o

Article history: Received 28 October 2014 Received in revised form 1 December 2014 Accepted 8 December 2014 Available online 23 December 2014 Keywords: Air foam Foam cement Lightweight pavement materials

a b s t r a c t This research investigates unit weight and strength development over curing time of Lightweight Cellular Cemented (LCC) Bangkok clay with various cement contents between 100 and 250 kg/m3 and the air foam contents between 0 and 50% of the volume of wet soil. The studied water content of the LCC Bangkok clay is at workable state, which is 2 times the liquid limit. This research ascertains that the waste excavated soft Bangkok clay can be stabilized by cement and air foam to be a sustainable lightweight pavement material. As the cement content increases and air content decreases, the unit weight and unconfined compressive strength of the LCC Bangkok clay increases. Based on a critical analysis of the test data, mix design charts for lightweight pavement materials specified by the local national road authority, which are subgrade, selected materials and subbase are proposed. These charts are useful as a practical tool for approximating the input air content and cement content to attain the target unit weight for each pavement material. © 2014 Elsevier B.V. All rights reserved.

1. Introduction Due to a large number of construction activities in metropolitan Bangkok, there is presently an abundance of excavated soft Bangkok clay. This excavated soft clay has high water content and is not suitable as a construction material; therefore it is normally transported for landfill. In recent years, there has been an environmental push worldwide to continually seek new reuse applications for various waste materials (Puppala et al., 2011; Arulrajah et al., 2012, 2014; Rahman et al., 2014). This excavated soft clay can be used as a sustainable construction material, when its engineering properties are improved. Cement stabilization is one of the extensively used soil improvement techniques. It is commonly used in road construction, airport, embankment and canal linings to increase strength and bearing capacity and to reduce swelling of problematic soils. Many researchers have reported on pavement and geotechnical applications of cement stabilized soil (Porbaha, 1998; Porbaha et al., 1998; Miura et al., 2001; Horpibulsuk et al., 2006; Horpibulsuk et al., 2005; Chinkulkijniwat and Horpibulsuk, 2012; Lorenzo and Bergado, 2006; Arulrajah et al., 2009; Horpibulsuk et al., 2011; Voottipruex et al., 2011; Horpibulsuk et al., 2012b; Du et al., 2013; Shen et al., 2013; Teerawattanasuk and Voottipruex, 2014). A combination of cement and air foam has been recently researched and applied in civil engineering and infrastructure applications as fill and pavement materials to primarily reduce the load on soft clay ⁎ Corresponding author. Tel.: +66 44 22 4322, +66 89 767 5759, fax: +66 44 22 4607. E-mail addresses: [email protected] (C. Teerawattanasuk), [email protected] (P. Voottipruex), [email protected], [email protected] (S. Horpibulsuk).

http://dx.doi.org/10.1016/j.clay.2014.12.012 0169-1317/© 2014 Elsevier B.V. All rights reserved.

deposits (Tsuchida, 1995; Tsuchida et al., 1996; Tsuchida et al., 2001; Tsuchida and Kang, 2002; Tsuchida and Kang, 2003) similar to other lightweight fill materials such as expanded polystyrene (Deng and Xiao, 2010), tires (Nakhaei et al., 2012) and lightweight concrete (Chindaprasirt and Rattanasak, 2011). This stabilized material is designated as Lightweight Cellular Cemented (LCC) material (Horpibulsuk et al., 2014a). Besides the low unit weight, the LCC material exhibits moderately high shear strength and low compressibility compared with untreated soil (Tsuchida and Egashira, 2004; Watabe et al., 2004) and natural aggregates. The shear strength of LCC soil depends primarily on the cement content. The higher cement content results in the higher Unconfined Compressive Strength (UCS) (Otani et al., 2002; Kim et al., 2008). Recently, Horpibulsuk et al. (2012a, 2013 and 2014b) and Neramitkornburi et al. (2015a,b, accepted for publication) have investigated unit weight, UCS, compressibility and durability against wetting and drying characteristics of LCC Bangkok clay, kaolin and bentonite at various water contents, cement contents, air contents and curing times. They have illustrated that the addition of air content is not always positive; i.e., at low water content, the clay viscosity is high and prevents the air bubble entry into the pore space, resulting in insignificant reduction in unit weight even with the increase in air content. The workable state, where the addition of air foam significantly reduces the unit weight of LCC clay, was found at approximately 1.5 to 2.0 times the liquid limit. Even with the available research on the unit weight and strength of LCC material, a practical design chart for this LCC material with reference to the strength requirement specified by the local national road authority has not been developed and will be the focus of this

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319

Volume

Weight

soil solid

water in soil

VAF

Air-Foam

Vw

Water

Ww

VC

Cement

WC

VS

Soil Solid

WS

WAF

cement

air-foam

a)

b)

c)

Fig. 1. a) Saturated soil b) Lightweight cellular cemented soil c) Phase diagram.

paper. This paper aims to investigate UCS of LCC Bangkok clay to ascertain it as a sustainable lightweight pavement material. The UCS of LCC Bangkok clay at various cement contents and air contents is moreover analyzed to develop practical design charts. The strength requirement specified by the Department of Highways, Thailand is used as the standard for this development. Three charts are proposed for LCC subbase, selected materials A and B and subgrade materials. This research will enable excavated soft Bangkok clay traditionally destined for landfill to develop sustainable lightweight pavement materials, which are significant in terms of engineering, economical and environmental perspectives. This research outcome can be applied to other marine clays such as Changi clay in Singapore, Ariake clay in Japan, and Pusan clay in Korea (Ohtsubo et al., 2000; Tanaka et al., 2001; Arulrajah et al., 2007; Arulrajah and Bo, 2008; Chu et al., 2009).

Unconfined Compressive Strength (kPa)

1200 Air Foam Content = 30%

3

Cement 250 kg/m 3 Cement 200 kg/m 3 Cement 150 kg/m 3 Cement 100 kg/m

1100 1000 900 800 700 600 500 400 300 200

Table 1 Experimental results of unconfined compressive strength and total unit weight.

100 7

14

21

28

35

42

49

Curing Time (days)

Mixing conditions

Average total unit weight (kN/m3)

Unconfined compressive strength at different curing times (kPa) 7 days

14 days

28 days

45 days

C100:AF0 C100:AF10 C100:AF20 C100:AF30 C100:AF40 C100:AF50 C150:AF0 C150:AF10 C150:AF20 C150:AF30 C150:AF40 C150:AF50 C200:AF0 C200:AF10 C200:AF20 C200:AF30 C200:AF40 C200:AF50 C250:AF0 C250:AF10 C250:AF20 C250:AF30 C250:AF40 C250:AF50

13.7 13.0 12.8 12.0 10.3 – 14.4 13.6 13.3 12.7 11.1 10.8 14.6 13.9 13.4 12.9 11.2 10.9 14.8 14.4 14.0 13.1 12.5 11.9

266.52 173.72 141.60 128.35 37.55 NA* 518.77 337.54 307.45 241.79 66.70 64.92 537.19 492.43 440.60 260.93 137.57 111.85 1091.99 894.76 738.97 546.55 337.50 183.21

274.54 186.72 164.20 139.38 47.98 NA* 597.55 424.09 419.84 276.49 69.07 65.57 815.67 803.18 463.42 358.26 209.71 131.70 1222.57 1051.36 930.42 674.04 512.60 341.50

454.19 274.69 262.86 167.15 48.97 NA* 629.08 497.48 456.72 304.33 138.28 96.41 1059.70 820.60 609.89 393.12 280.21 139.41 1468.60 1283.28 966.06 834.89 638.36 364.31

623.05 331.65 266.24 191.84 59.16 NA* 864.70 563.78 466.75 379.58 140.78 138.91 1099.26 872.29 693.92 445.12 392.91 171.62 1523.55 1355.48 1010.64 857.62 650.36 366.33

(a) Effect of cement content and curing time 1600

Unconfined Compressive Strength (kPa)

Curing Time 28 days 1400 3

Cement 250 kg/m 3 Cement 200 kg/m 3 Cement 150 kg/m 3 Cement 100 kg/m

1200 1000 800 600 400 200 0 0

10

20

30

40

50

Air Foam Content (%)

(b) Effect of air content Fig. 2. Effect of cement content, curing time and air content on UCS of LCC clay.

C = cement; AF = air foam; CXXX = mix proportion of cement weight to wet soil volume in (kg/m3); AFYY = mix proportion of air-foam content to wet soil volume in (%); NA* = not available data due to the mixture of specimen is unstable (large segregation of mixture specimen).

320

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15.0 14.5

Average Total Unit Weight (kN/m3)

Table 2 Strength requirement for pavement materials according to the Department of Highways, Thailand.

Curing Time 28 days

14.0 13.5 13.0 12.5

Material standard

qu (kPa)

1.) Soil cement base (DH-S 204/2533) 2.) Soil cement subbase (DH-S 206/2532) 3.) Selected material “A” (DH-S 208/2532) 4.) Selected material “B” (DH-S 209/2532) 5.) Subgrade (DH-S 102/2532)

1723.00 689.00 407.00 331.80 294.20

12.0 11.5

specific gravity of soil is 2.60. Liquid Limit (LL), Plastic Limit (PL) and Plasticity Index (PI) are 69%, 29% and 40%, respectively, which are within the typical ranges of soft Bangkok clay as reported by Horpibulsuk and Rachan (2004) and Horpibulsuk et al. (2007) (LL = 70 ± 14 % and PL = 27 ± 4 %). The clay mineral of Bangkok clay is primarily montmorillonite followed by illite and mica. According to the Unified Soil Classification System, this soil is classified as high plastic clay (CH).

3

Cement 250 kg/m 3 Cement 200 kg/m 3 Cement 150 kg/m 3 Cement 100 kg/m

11.0 10.5 10.0 0

10

20

30

40

50

Air Foam Content (%) Fig. 3. Effect of air content and cement content on unit weight of LCC clay.

2.2. Methods

2. Materials and methods 2.1. Materials Tested materials include soft Bangkok clay from Pathumthani province, Type I Portland Cement (PC), and chemical foaming agent. The chemical composition of PC is mainly 20.90% SiO2, 4.76% Al2O3, 3.41% Fe2O3, 65.0% CaO, 1.25% MgO, 2.71% SO3, 0.24% Na2O, and 0.35% K2O. The air foam was prepared by mixing the foaming agent with water at a ratio of 1:40 by volume, as recommended by the manufacturer and transferred into the foam producing machine. The soft Bangkok clay studied is a disturbed sample with light brown color. Natural water content is 60%, unit weight is 17.8 kN/m3 and

Horpibulsuk et al. (2014b) showed that addition of either water or air foam can reduce the unit weight of LCC material for a particular cement content. However, the addition of air foam is more advantageous in terms of strength development. In other words, for the same unit weight but with different air contents and water contents, the strength of LCC material with a higher water content is lower due to higher water/cement ratio. As such, the studied water content is fixed at twice the liquid limit, which is 138%, while the air content is varied to reduce the unit weight of the LCC Bangkok clay. The clay slurry (at water content of 138%) at a required cement content was thoroughly mixed with cement for 6 min and then blended with air foam for additional 4 min. The studied air foam contents (AF) were 0%, 10%, 20%, 30%, 40% and 50% of volume of wet soil and the cement contents were 100, 150, 200 and 250 kg/m3 of wet soil. Subsequently, the

Air Foam Content (%) 0

10

20

30

40

50

1600

11.5

3

Cement Content 250 kg/m Curing Time 45 days

12.0

12.5

1200

3

1000

13.0

2

1 800

13.5

600

14.0

2 400

14.5

Total Unit Weight Unconfined Compressive Strength

15.0

200 0

10

20

30

40

50

Air Foam Content (%) Fig. 4. Relationship between UCS and unit weight versus air content of LCC clay at C = 250 kg/m3.

Average Total Unit Weight (kN/m3)

Unconfined Compressive Strength (kPa)

1400

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were tested to check for consistency. In total, 432 specimens were tested in this study.

LCC mixture was casted in a cylindrical mold of 5 cm in diameter and 10 cm in height for an unconfined compression (UC) test. After 24 h, the cylindrical specimens were dismantled and wrapped in vinyl bags and they were cured in a humid room of constant temperature (20 ± 2 °C) for 7, 14, 28 and 45 days. The unit weight of the specimens was measured and UC test was next undertaken according to ASTM D 2166. In each curing period and mixing proportion, three specimens

2.3. Calculation of mixing proportion The clay slurry includes 2 phases: soil solid and water as shown in Fig. 1a. After mixing with cement and air foam, the mixture becomes a

Air Foam Content (%) 0

10

20

30

40

50

600

AF < 6%

3

Mixing Cement Content 150 kg/m Curing Time 7 days

500

3

γ = 14.4 kN/m

Subbase Material AF < 19%

Selected Material A Selected Material B

400

Subgrade Material

3

γ = 13.6 kN/m 3 γ = 13.3 kN/m

100

Subgrade Material

200

Selected Material B

300

Selected Material A

Unconfined Compressive Strength (kPa)

AF < 11%

3

γ = 12.7 kN/m

3

Unconfined Compressive Strength

γ = 11.1 kN/m 3 γ = 10.8 kN/m

0 0

10

20

30

40

50

40

50

Air Foam Content (%)

(a) C = 150 kg/m3 Air Foam Content (%) 0

10

20

30

600 3

Mixing Cement Content 200 kg/m Curing Time 7 days

3

γ = 14.6 kN/m

3

500

Unconfined Compressive Strength

γ = 13.9 kN/m

3

γ = 13.4 kN/m 400

Subbase Material AF < 24%

300

Selected Material A

AF < 27%

Selected Material B

3

γ = 12.9 kN/m

100

Subgrade Material

200

Selected Material B

Subgrade Material Selected Material A

Unconfined Compressive Strength (kPa)

AF < 17.5%

3

γ = 11.2 kN/m 3 γ = 10.9 kN/m

0 0

10

20

30

40

Air Foam Content (%)

(b) C = 200 kg/m3. Fig. 5. Design charts for LCC Bangkok clay as pavement materials.

50

322

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Air Foam Content (%) 0

10

20

30

40

50

1200 3

Mixing Cement Content 250 kg/m & Curing Time 7 days 1000

3

γ = 14.8 kN/m

Unconfined Compressive Strength

700 600

AF < 22% Subbase Material

500

Selected Material A

Subgrade Material

800

3

γ = 14.4 kN/m Selected Material B

900

Selected Material Selected Material A A

Subbase Material

Unconfined Compressive Strength (kPa)

1100

3

γ = 14.0 kN/m

3

γ = 13.1 kN/m

AF < 36%

400 3

γ = 12.5 kN/m

Selected Material B 300

AF < 41.5% Subgrade Material

200

3

γ = 11.9 kN/m

AF < 44%

100 0

10

20

30

40

50

Air Foam Content (%)

(c) C = 250 kg/m3 Fig. 5 (continued).

four phase material as shown in Fig. 1b. Using Fig. 1c, the weight of cement (Wc) and air content volume (VAF) to be mixed with clay slurry are determined as follows: Wc ¼ C  ðVs þ Vw Þ

ð1Þ

VA F ¼ AF  ðVs þ Vw Þ

ð2Þ

Fig. 4 shows a typical relationship between UCS and total unit weight versus AF. The relationship is useful for designing the LCC clay in practice. For example, the AF required for a UCS of 800 kPa after 45 days of curing can be approximated as follows: draw a horizontal line from UCS of 800 kPa to meet the UCS line; therefore the required AF is 32%. The unit weight is then approximated and is 12.95 kN/m3. Similarly, AF and UCS can be approximated for the required total unit weight. 4. Design charts for LCC clay as pavement materials

where Vs is the volume of soil solid, Vw is the volume of water, Vc is the volume of cement, and C is the cement content. 3. Test results Fig. 2 and Table 1 show the effect of cement content, air content and curing time on UCS and unit weight of LCC Bangkok clay. UCS increases significantly with increasing cement content even after 28 days of curing (Fig. 2a). It is clearly shown from Table 1 that the UCS increases as the air content decreases and the curing time increases. For instance, the UCS values of specimens at C = 250 kg/m3 and AF = 0% are 1092.0, 1222.6, 1468.6 and 1523.6 kPa for 7, 14, 28 and 45 days of curing, respectively. When 10% air foam is added, the UCS values reduce to 894.8, 1051.4, 1283.3 and 1355.5 kPa, respectively. The significant UCS reduction with air content is also evident in Fig. 2b, showing that the UCS and air content relationship can be approximately represented by linear function. Besides strength, unit weight is a requirement for LCC clay applications. Fig. 3 shows the effect of air content and cement content on the unit weight of the LCC Bangkok clay for C = 100 kg/m3, 150 kg/m3, 200 kg/m3 and 250 kg/m3. The unit weight increases with increasing cement content and decreasing air content. The specimen with C = 250 kg/m3 shows the highest unit weight for the air foam contents ranging from 0% to 50%. While the specimens with C = 200 kg/m3 and 150 kg/m3 show more or less the same unit weight at the same air foam contents. The specimen with C = 100 kg/m3 shows the lowest unit weight.

There are 5 pavement material standards specified by the Department of Highways, Thailand including: soil–cement base (DH-S 204/2533), soil cement subbase (DH-S 206/2532), selected material A (DH-S 208/2532), selected material B (DH-S 209/2532) and subgrade material (DH-S 102/2532). The selected materials A and B are generally between subgraded and subbase for the purpose of increasing pavement thickness. Table 2 summarizes the UCS requirement for pavement materials. From Tables 1 and 2, it is noted that the LCC Bangkok clay with C = 100 kg/m3 at 7 days of curing is not suitable as the subgrade material for all air contents because the UCS values of all specimens are lower than the requirement (less than 294.20 kPa). Fig. 5 shows the design charts for C = 150, 200 and 250 kg/m3, respectively for different pavement materials. It is evident that the LCC Bangkok clay is not suitable as the base material. The LCC Bangkok clay can be used as the subbase material only when C = 250 kg/m3 where the minimum unit weight is about 13.8 kN/m3 for AF = 22%. The following is the summary of the test data: Selected material A: (1) C = 150 kg/m3 and AF = 0% to 6% where unit weight ranging from 14.4 to 13.9 kg/m3 (2) C = 200 kg/m 3 and AF = 0% to 17.5% where unit weight ranging from 14.6 to 13.5 kg/m3 (3) C = 250 kg/m3 and AF = 0% to 30% where unit weight ranging from 14.8 to 13.0 kg/m3.

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Selected material B: (1) C = 150 kg/m 3 and AF = 0% to 11% where unit weight ranging from 14.4 to 13.6 kg/m3 (2) C = 200 kg/m3 and AF = 0% to 24% where unit weight ranging from 14.6 to 13.2 kg/m3 (3) C = 250 kg/m3 and AF = 0% to 41.5% where unit weight ranging from 14.8 to 12.4 kg/m3. Subgrade material: (1) C = 150 kg/m 3 and AF = 0% to 19% where unit weight ranging from 14.4 to 13.3 kg/m3 (2) C = 200 kg/m3 and AF = 0% to 27% where unit weight ranging from 14.6 to 13.0 kg/m3 (3) C = 250 kg/m3 and AF = 0% to 44% where unit weight ranging from 14.8 to 12.2 kg/m3. 5. Conclusions This research ascertains that the excavated soft Bangkok clay, traditionally destined for landfill, can be used to develop sustainable lightweight pavement materials, which are significant from engineering, economical and environmental perspectives. A typical Bangkok clay from Pathumthani province, having a liquid limit of 69% and plastic index of 40%, is studied. The UCS of LCC Bangkok clay increases with increasing cement content and curing time and decreasing air content. Three mix design charts for 4 pavement materials specified by the Department of Highways, Thailand including soil cement subbase, selected material A, selected material B and subgrade material are presented. These charts are useful as a practical tool to approximate an input of air foam and cement to attain the target unit weight for each pavement material. Acknowledgment This research was supported by the Thailand Research Fund under the TRF Senior Research Scholar program Grant No. RTA5680002. The last author acknowledges the financial support from the Suranaree University of Technology and the Office of Higher Education Commission under NRU project of Thailand. References Arulrajah, A., Bo, M.W., 2008. Characteristics of Singapore marine clay at Changi. Geotech. Geol. Eng. 26, 431–441. Arulrajah, A., Bo, M.W., Nikraz, H., Balasubramaniam, A.S., 2007. Dissipation testing of Singapore marine clay by piezocone tests. Geotech. Geol. Eng. 25, 647–656. Arulrajah, A., Abdullah, A., Bo, M.W., Bouazza, A., 2009. Ground improvement techniques for railway embankments. Ground Improv. 162 (1), 3–14. Arulrajah, A., Piratheepan, J., Bo, M.W., Sivakugan, N., 2012. Geotechnical characteristics of recycled crushed brick blends for pavement sub-base applications. Can. Geotech. J. 49 (7), 796–811. Arulrajah, A., Disfani, M.M., Horpibulsuk, S., Suksiripattanapong, C., Prongmanee, N., 2014. Physical properties and shear strength response of recycled construction and demolition materials in unbound pavement base/subbase pavement. Constr. Build. Mater. 58, 245–257. Chindaprasirt, P., Rattanasak, U., 2011. Shrinkage behavior of structural foam lightweight concrete containing glycol compounds and fly ash. Mater. Des. 32, 723–727. Chinkulkijniwat, A., Horpibulsuk, S., 2012. Field strength development of repaired pavement using the recycling technique. Q. J. Eng. Geol. Hydrogeol. 45 (2), 221–229. Chu, J., Bo, M.W., Arulrajah, A., 2009. Reclamation of a slurry pond in Singapore. Geotech. Eng. 162 (GE1), 13–20. Deng, A., Xiao, Y., 2010. Measuring and modeling proportion-dependent stress–strain behavior of EPS-sand mixture. Int. J. Geomech. 10, 214–222. Du, Y.J., Wei, M.L., Jin, F., 2013. Laboratory investigation on strength properties of cement stabilized zinc-contaminated clay. Eng. Geol. 167 (17), 20–26. Horpibulsuk, S., Rachan, R., 2004. Novel approach for analyzing compressibility and permeability characteristics of Bangkok clayey soils. Proc. 15th Southeast Asian Geotechnical Engineering Conference, pp. 3–8.

323

Horpibulsuk, S., Miura, N., Nagaraj, T.S., 2005. Clay–water/cement ratio identity of cement admixed soft clay. J. Geotech. Geoenviron. Eng. ASCE 131 (2), 187–192. Horpibulsuk, S., Katkan, W., Sirilerdwattana, W., Rachan, R., 2006. Strength development in cement stabilized low plasticity and coarse grained soils: laboratory and field study. Soils Found. 46 (3), 351–366. Horpibulsuk, S., Shibuya, S., Fuenkajorn, K., Katkan, W., 2007. Assessment of engineering properties of Bangkok clay. Can. Geotech. J. 44 (2), 173–187. Horpibulsuk, S., Rachan, R., Suddeepong, A., Chinkulkijniwat, A., 2011. Strength development in cement admixed Bangkok clay: laboratory and field investigations. Soils Found. 51 (2), 239–251. Horpibulsuk, S., Suddeepong, A., Chinkulkijniwat, A., Liu, M.D., 2012a. Compressibility of lightweight cemented clays. Appl. Clay Sci. 69, 11–21. Horpibulsuk, S., Chinkulkijniwat, A., Cholphatsorn, A., Suebsuk, J., Liu, M.D., 2012b. Consolidation behavior of soil cement column improved ground. Comput. Geotech. 43, 37–50. Horpibulsuk, S., Rachan, R., Suddeepong, A., Liu, M.D., Du, Y.J., 2013. Compressibility of lightweight cemented clays. Eng. Geol. 159, 59–66. Horpibulsuk, S., Suddeepong, A., Suksiripattanapong, C., Chinkulkijniwat, A., Arulrajah, A., Disfani, M.M., 2014a. Water-void/cement ratio identity of lightweight cellular cemented material. J. Mater. Civ. Eng. 26 (10) (06014021(1–10)). Horpibulsuk, S., Wijichot, A., Neramitkornburee, A., Shen, S.L., Suksiripattanapong, C., 2014b. Factors influencing unit weight and strength of lightweight cemented clay. Q. J. Eng. Geol. Hydrogeol. 47, 101–108. Kim, Y.T., Kim, H.J., Lee, G.H., 2008. Mechanical behavior of lightweight soil reinforced with waste fishing net. Geotext. Geomembr. 26, 512–518. Lorenzo, G.A., Bergado, D.T., 2006. Fundamental characteristics of cement-admixed clay in deep mixing. J. Mater. Civ. Eng. 18 (2), 161–174. Miura, N., Horpibulsuk, S., Nagaraj, T.S., 2001. Engineering behavior of cement stabilized clay at high water content. Soils Found. 41 (5), 33–45. Nakhaei, A., Marandi, S.M., Sani Kermani, S., Bagheripour, M.H., 2012. Dynamic properties of granular soils mixed with granulated rubber. Soil Dyn. Earthq. Eng. 43, 124–132. Neramitkornburi, A., Horpibulsuk, S., Shen, S.L., Arulrajah, A., Disfani, M.M., 2014. Engineering properties of lightweight cellular cemented clay-fly ash material. Soils Found. 55 (2). Neramitkornburi, A., Horpibulsuk, S., Shen, S.L., Arulrajah, A., Disfani, M.M., 2015a. Engineering properties of lightweight cellular cemented clay-fly ash material. Soils Found Vol.55 No.2 (Accepted for publication on November 20, 2014). Neramitkornburi, A., Horpibulsuk, S., Shen, S.L., Chinkulkijniwat, A., Arulrajah, A., Disfani, M.M., 2015b. Durability against wetting-drying cycles of sustainable lightweight cellular cemented construction material comprising clay and fly ash wastes. Constr. Build. Mater (Accepted for publication on December 14, 2014). Ohtsubo, M., Egashira, K., Koumoto, T., Bergado, D.T., 2000. Mineralogy and chemistry, and their correlation with the geotechnical index properties of Bangkok clay: comparison with Ariake clay. Soils Found. 40 (1), 11–21. Otani, J., Mukunoki, T., Kikuchi, Y., 2002. Visualization for engineering property of in-situ light weight soils with air foams. Soils Found. 4 (3), 93–105. Porbaha, A., 1998. State of the art in deep mixing technology, Part I. Basic concepts and overview. Ground Improv. 2, 81–92. Porbaha, A., Tanaka, H., Kobayashi, M., 1998. State of the art in deep mixing technology: part II. Applications. Ground Improv. 2, 125–139. Puppala, A.J., Hoyos, L.R., Potturi, A.K., 2011. Resilient moduli response of moderately cement-treated reclaimed asphalt pavement aggregates. J. Mater. Civ. Eng. 23 (7), 990–998. Rahman, M.A., Imteaz, M., Arulrajah, A., Disfani, M.M., 2014. Suitability of recycled construction and demolition aggregates as alternative pipe backfilling materials. J. Clean. Prod. 66, 75–84. Shen, S.L., Wang, Z.F., Horpibulsuk, S., Kim, Y.H., 2013. Jet grouting with a newly developed technology: the twin-jet method. Eng. Geol. 152 (1), 87–95. Tanaka, T., Mishima, O., Tanaka, M., Park, S.Z., Jeong, G.H., Locat, J., 2001. Characterization of Yangsan clay, Pusan, Korea. Soils Found. 41 (2), 89–104. Teerawattanasuk, C., Voottipruex, P., 2014. Influence of clay and silt proportions on cement treated fine-grained soil. J. Mater. Civ. Eng. 26 (3), 420–428. Tsuchida, T., 1995. Super geo-material project in coastal zone. Proceedings of the International Symposium on Ocean Space Utilization COSU'95, Yokohama, pp. 22–31. Tsuchida, T., Egashira, K., 2004. The lightweight treated soil method: new geomaterials for soft ground engineering in coastal areas. A.A. Balkema Publisher, London. Tsuchida, T., Kang, M.S., 2002. Use of lightweight treated soil method in seaport and airport construction projects. Proceedings of the Nakase Memorial Symposium, Soft Ground Engineering in Coastal Areas. A.A. Balkema, Yokosuka, pp. 353–365. Tsuchida, T., Kang, M.S., 2003. Case studies of lightweight treated soil method in seaport and airport construction projects. Proceedings of the 12th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, Singapore, pp. 249–252. Tsuchida, T., Takeuchi, D., Okumura, T., Kishida, T., 1996. Development of light-weight fill from dredging. Proc. Environ. Geotech. 415–420. Tsuchida, T., Porbaha, A., Yamane, N., 2001. Development of a geomaterial from dredged bay mud. J. Mater. Civ. Eng. 13, 152–160. Voottipruex, P., Suksawat, T., Bergado, D.T., Jamsawang, P., 2011. Numerical simulations and parametric study of SDCM and DCM piles under full scale axial and lateral loads. Comput. Geotech. 38 (3), 318–329. Watabe, Y., Itou, Y., Kang, M.S., Tsuchida, T., 2004. One-dimensional compression of air-foam treated lightweight geo-material in microscopic point of view. Soils Found. 44 (6), 53–67.