The influence of admixtures type on the air-voids parameters of non-air-entrained and air-entrained high performance SCC

Construction and Building Materials 41 (2013) 109–124

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The influence of admixtures type on the air-voids parameters of non-air-entrained and air-entrained high performance SCC Beata Łaz´niewska-Piekarczyk ⇑ Silesian Technical University, Faculty of Civil Engineering, Department of Building Processes, Akademicka 5 Str., 44-100 Gliwice, Poland

h i g h l i g h t s " Admixtures type affects the properties of fresh and hardened HPSCC. " SP type significantly influences the porosity of HPSCC. " AFA type influences the porosity of non-air-entrained HPSCC. " AEA type influences the porosity of air-entrained HPSCC. " VMA type influences the porosity of air-entrained and non-air-entrained HPSCC.

a r t i c l e

i n f o

Article history: Received 1 March 2012 Received in revised form 8 October 2012 Accepted 21 November 2012 Available online 8 January 2013 Keywords: High performance self-compacting concrete (HPSCC) Superplasticizer (SP) Air-entraining admixture (AEA) Anti-foaming admixture (AFA) Viscosity modifying admixture (VMA) Workability Porosity Air-voids parameter

a b s t r a c t The influence of a type of new generation: superplasticizer (SP), air-entraining admixture (AEA), viscosity modifying admixture (VMA) and anti-foaming admixture (AFA) on the air-content, workability of high performance self-compacting concrete (HPSCC), is analyzed in the paper. The purpose of this study was to examine the influence of the type of admixtures on porosity and pore size distribution of HPSCC at constant water on cement ratio, type and volume of aggregate and volume of cement paste. The parameters of the air-voids of hardened HPSCC are also investigated. The results presented in the article demonstrated that admixtures from different sources cannot be used interchangeably, even if they appear to have a similar chemical composition. Ó 2012 Elsevier Ltd. All rights reserved.

1. Introduction Self-compacting concrete (SCC) has the ability to flow and consolidate under its own weight, making it well suited for applications with heavy reinforcement, complicated formwork, or where mechanical vibration would be difficult. High fluidity of SCC can cause the mixture to be unstable; therefore, the concrete must also be cohesive enough to fill any shape without segregation or bleeding. The flow ability and viscosity of a SCC mixture are controlled through the use of superplasticizers (SPs) and viscosity modifying admixtures (VMAs), respectively [1]. SP should be compatible with cement, but it should not increase the air content in SCC. The publication [2] indicates that the SP

⇑ Tel.: +48 032 2372294; fax: +48 032 2372737. E-mail address: [email protected] 0950-0618/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.conbuildmat.2012.11.086

causes reduction in total air-void surface areas and increases in air-void spacing factors. Research results [3] indicated that certain superplasticizer (SP) of new generation produce an excessive airentrainment remaining in the volume of the fresh mix and concrete, although the mix meets commonly accepted criteria of technical tests according to [4]. According to authors’ publication [5], polycarboxylate SPs usually have an air-entraining effect. With the use of polycarboxylate SPs, the air pores characterize with smaller diameters than pores formed as a result of lingosulphonic or naphthalene SPs functioning [6]. The inclusion of SP (sodium salt of a sulphonated napthalene–formaldehyde condensate) in cement paste, leads to a reduction in the total pore volume and to a refinement of the pore structures [7]. The dominant pore size is unaffected and the threshold diameter is reduced in the presence of SP. Research results cited in publication [3] indicate that the air-content in hardened SCC, as a side effect of SP acting, may amount to even 8.0%.

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The anti-foaming admixtures (AFAs) decrease effectively the air-content in SCC [8,9]. The components and their proportions used in the anti-foaming admixtures, as in SP, are known only to the producers. These ingredients could be mineral oils, silicone oils, organic modified silicones, hydrophobic constant molecules (silica, waxes, higher fatty acids soaps, alcohols and fatty acids), emulsifiers, polyalcohol or alcohol derivatives of organic compounds. Mixes of the active components mentioned above could have a synergetic effect. There are no research results on the impact of AFA type on concrete’s porosity. Thus, it is advisable to carry on proper tests for verification of the influence of AFA type on the air-entrainment, rheological properties and porosity characteristic of concrete. In case of air-entrained SCC, as with the non-entrained SCC, achieving the suitable air void characteristics is also a difficult task [10–12]. Air bubbles in fresh concrete are inherently unstable [13– 16]. The air bubbles can move more freely in concrete when it is highly fluid; therefore, there is increased occurrence of bubble coalescence and rupturing. To a certain degree, a SCC mixture with a high viscosity (usually accompanying a lower slump flow) prevents bubbles from rupturing or coalescing by creating a ‘‘cushion effect’’ for the air voids to remain unaffected by mixing and other disturbances [15]. Increasing slump flow increases the demand for AEA to entrain a given volume of air [17–19]. The flow ability and viscosity of a SCC mixture are controlled through the use of SP and viscosity modifying admixtures (VMAs), respectively. Research results [12], showed that VMA influences on air-voids parameters of the air-entrained SCC. The question is whether another type of VMA has a similar effect in this regard? Many inorganic electrolytes and polar organic materials influence the foaming ability of surfactants [1,15]. Because of the complexity of modern AEAs and other chemical admixtures, it is impossible to generalize the effects of their interactions with surfactants on the air entrainment. The results presented in study [1], demonstrated that admixtures from different sources cannot be used interchangeably, even if they appear to have a similar chemical composition. Taking into account the above, the effects of the admixtures type in case of HPSCC should be examined. Furthermore, whether the type and interaction of SP, VMA, and AFA (in case on non-airentrained HPSCC) and SP, AEA and VMA (in case of air-entrained HPSCC) affect the values of air voids parameters? The article presents the development of HPSCC with different types of new generation SP: SP1 (with air entraining side effect) and SP2 (without entraining side effect) and different new generation type of VMA, AEA and AFA. It establishes the following main aim of the admixtures use (Table 1).

The study was then carried out on the fresh and hardened properties of different HPSCC at constant water on cement ratio, type and volume of aggregate and volume of cement paste. 2. Research significance The research results [12] proved that the admixtures significantly influence air voids parameters of SCC and consequently affect its frost resistance. The effects of the admixtures in case of HPSCC should be examined. It is important to determine the positive and negative effects of SP type and modification of the non-airentrained and air-entrained HPSCC by different type of VMA and AFA. The effects of different types of admixtures actions may influence the values of HPSCC air-voids parameters, because the air voids of concrete influence its frost resistance and compressive strength. 3. Materials and description of the tests The experimental investigation was carried out in two phases. In Phase 1, tests were carried out on fresh high performance selfcompacting concrete with different type of SP, VMA, AEA and AFA. Phase 2 investigated the properties of the hardened HPSCC. 3.1. Examined materials 3.1.1. Cement, mineral additives and aggregates A type CEM I 42.5 R cement was used. Chemical and physical properties of cement are shown in Table 2. The chemical and physical properties of a silica fume (SF) are shown in Table 3. Local natural sand, fine and eight-millimeter maximum size gravel aggregates, were used in concrete mix, respectively. The properties of sand and gravel aggregate are presented in Tables 4 and 5. Sand content in the aggregate is 44.4%. Water was used according to EN 1008. 3.1.2. Chemical admixtures The main aim of the use of the admixtures was presented in Table 1. The aim of the admixtures use, symbol of series of HPSCC and type of admixtures are presented in Table 6. The properties of admixtures are presented in Table 7–10. SP 1 and SP 2 composed of different type of polycarboxyl ether, having total solid content of 30.0% were used. The chemical composition of SP, VMA, AEA and AFA is a proprietary commercial patent. 3.2. Phase 1: Mix proportion and its preparation

Table 1 The main aim of use of the admixtures. Combination of admixtures

The main aim of the admixtures use

‘‘Air-entraining’’ SP1

The air-entrained HPSCC (as a result of SP1side effect) Elimination of segregation as a result of SP1 action Elimination of too high air-content (as a result of SP1 side effect) in HPSCC Elimination of segregation as a result of SP1 and AFA action Non-air-entrained HPSCC Elimination of segregation as a result of SP2 action Intentionally air-entrained HPSCC

‘‘Air-entraining’’ SP1 + VMA ‘‘Air-entraining’’ SP1 + AFA ‘‘Air-entraining’’ SP1 + AFA + VMA ‘‘Non-air-entraining’’ SP2 ‘‘Non-air-entraining’’ SP2 + VMA ‘‘Non-air-entraining’’ SP2 + AEA ‘‘Non-air-entraining’’ SP2 + AEA + VMA

Elimination of segregation as a result of SP2 and AEA action

Twenty-six high performance self-compacting concrete mixtures (Tables 11–17) were made to study the effect of type of SP, VMA, AFA and AEA on the properties of HPSCC. In comparison to normal strength concrete, high performance concrete are much more homogenous and less porous. Strength and other properties of high performance concrete grow with the higher number of contacts among particles, reduced porosity and defects within the structure. Reduction of porosity is achieved by using a low water/binder (w/b) ratio, adding SP (providing sufficient workability in fresh state), and replacing a portion of cement with pozzolanic additives. Less water in the composition of high performance concrete than in normal strength concrete reduces the space between cement grains and mineral additives in the fresh state. In this way capillary porosity is also reduced and so is the space to be filled with the products of hydration [20,21]. A reduction in water/binder ratio and the use of mineral additives have a positive effect on the improvement in the interface between cement matrix and aggregates as the weakest link in the concrete structure. The

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Table 2 The chemical and physical properties of CEM I 42.5 R. Chemical analyses (%) SiO2

CaO

Al2O3

Fe2O3

MgO

Na2Oe

SO3

21.61

64.41

4.46

2.24

1.25

0.4

3.1

Specific surface blaine (cm2/g)

Specific gravity (g/cm3)

Compressive strength (MPa)

3830

3.1

69.3

Setting time, vicat test (min) Initial setting

Final setting

175

–

Table 3 The chemical and physical properties of silica fume. Specific surface (m2/kg)

Chemical analyses (%) SiO2

CaO

Al2O3

Fe2O3

MgO

Na2O

SO3

K2O

92.8

0.7

0.6

0.3

1.32

0.3

0.8

0.5

Table 4 The chemical and physical analysis of sand 0/2 mm. Parameters

Result

SiO2 Fe2O3 Al2O3 CaO MgO Clay CaCo3 Moisture Loss on ignition pH Density

>99.3% 300 ppm Max 2500 ppm Max 250 ppm Max 50 ppm Max 0.3% Max 0.5% Max <0.1% Max <0.3% Max Neutral 2.65 gm/cc

Table 5 The properties of sand and gravel. Property

Sand 0/2 (mm)

Gravel 0/8 (mm)

The content of mineral dust The content of organic substances Bulk density (qnz) Flatness index Absorptivity

0.67%, Category f3 Absence 1.74 kg/dm3 – –

0.48%, Category f3 Absence 1.69 kg/dm3 6.2%, Category FI10 0.62%

most efficient admixture to cement is silica fume. Because of its very small grains (about 10 times smaller than a cement grain) and large specific area, silica fume has a positive effect on the increase in density of the area surrounding cement particles and, because of higher reactivity, on accelerated hydration. Furthermore, silica fume reacts with free lime – the poorest component of cement – thereby making CSH gel [22]. Considering that high performance concrete contain high quantities of binders, the size of maximum aggregate grain size should be reduced. In case of the HPSCC, gravel 0/8 mm was used. The proportion of cement, silica fume, water, coarse aggregate and sand was kept constant (Table 11). The following admixtures were used (Table 12–17): SP1 (with air-entraining side effect), SP2 (without air-entraining side effect), AFA1–AFA6; AEA1, AEA 2; VMA1, VMA2 and VMA3. Because the consistency of the fresh concrete influences the air-content in SCC [23], the dosages of the SP were conformed to the same slump flow class (SF2) of SCC. AEA was conformed to the air content value 4–7%. The VMA was used to reach a VS2 viscosity class and the AFA agent to reduce too high air content in case of non-air entrained HPSCC (the air content less than 2%). The concrete was produced in a horizontal pan mixer with capacity of 0.070 m3. In each case, volume of this mixture was 60 dm3.

18,000

Author’s research results showed that in case of a longer mixing time of HPSCC, smaller dosage of SP is needed than in case of a short mixing time. Short mixing time often leads to overdosing amount of SP. The sand and coarse aggregate were first mixed for 1 min. Then, cement and silica fume were added with the water. After mixing for 10 min, the SP was introduced and allowed to mix for an additional 5 min. Finally, remaining admixtures (according to Tables 11–17) were added and mixed for the additional 3 min. 3.3. Methodology of test of HPSCC properties 3.3.1. Tests on fresh HPSCC properties The tests of fresh high performance self-compacting concrete were carried out after 20 min, because the SP liquefaction efficiency increases after time. Before the test concrete mixture was mixed for 5 min. The main aim of this step of the research is to compress the influence of admixtures type on workability and air volume of

Table 6 Symbol of series of HPSCC and type of admixtures. The aim of the admixtures use

Symbol

Type of admixtures

The air-entrained HPSCC (as a result of SP1 side effect) Non-air-entrained HPSCC

S1

SP1

S2

SP2

Elimination of segregation as a result of SP1 action

S1V1 S1V2 S1V3

SP1 + VMA1 SP1 + VMA2 SP1 + VMA3

Elimination of segregation as a result of SP2 action

S2V1 S2V2 S2V3

SP2 + VMA1 SP2 + VMA2 SP2 + VMA3

Elimination of too high air-content (as a result of SP1 side effect) in HPSCC

S1A1 S1A3 S1A4 S1A5 S1A6

SP1 + AFA1 SP1 + AFA3 SP1 + AFA4 SP1 + AFA5 SP1 + AFA6

Elimination of segregation as a result of SP1 and AFA action

S1A1V1 S1A2V1 S1A3V1 S1A3V2 S1A1V2 S1A1V3

SP1 + AFA1 + VMA1 SP1 + AFA2 + VMA1 SP1 + AFA3 + VMA1 SP1 + AFA3 + VMA2 SP1 + AFA1 + VMA2 SP1 + AFA1 + VMA3

Intentionally air-entrained HPSCC

S2A1 S2A2

SP2 + AEA1 SP2 + AEA2

Elimination of segregation as a result of SP2 and AEA action

S2A1V1 S2A1V2 S2A1V3 S2A2V1 S2A2V2

SP2 + AEA1 + V1 SP2 + AEA1 + V2 SP2 + AEA1 + V3 SP2 + AEA2 + V1 SP2 + AEA2 + V2

B. Łaz´niewska-Piekarczyk / Construction and Building Materials 41 (2013) 109–124

112 Table 7 The properties of SPs.

Table 12 The dosage of SP by weight of total binder (%).

Property Main base 3

Specific gravity at 20 °C (g/cm ) pH-value at 20 °C Chloride ion content (mass%) Alkali content (Na2O eqiv.) (mass%)

SP1

SP2

Symbol

SP1

SP2

Polycarboxyl ether 1.07 ± 0.02 6.5 ± 1.0 60.1 1.5

Polycarboxyl ether 1.05 ± 0.02 6.5 ± 1.5 1.3 1.3

S1 S2

2.75 –

– 4.34

S1 – SP1, ‘‘air-entraining’’, S2 – SP2, ‘‘non-air-entraining’’.

Table 13 The dosage of SP and VMA by weight of total binder, %. Table 8 The properties of anti-foaming admixtures. Symbol

Main base

AFA1 AFA2 AFA3

Polyalcohol Froth breaker on the PDMS basis/silicone oil/hydrophobic silica Froth breaker on the basis of alcohol derivative of saturated fatty alcohol, mineral oil and PE wax Modified polyalcohol Alkoxyl derivative of fatty alcohol, 100% Froth breaker on the basis of mineral oil or amidol wax

AFA4 AFA5 AFA6

Symbol

SP1

SP2

VMA1

VMA2

VMA3

S1V1 S1V2 S1V3 S2V1 S2V2 S2V3

3.28 3.67 4.90 – – –

– – – 4.92 5.22 5.05

0.15 – – 0.58 – –

– 0.25 – – 1.37 –

– – 0.03 – – 0.07

S1V1 – SP1 + VMA1, S1V2 – SP1 + VMA2, S1V3 – SP1 + VMA3, S2V1 – SP2 + VMA1, S2V2 – SP2 + VMA2, S2V3 – SP2 + VMA3.

Table 14 The dosage of SP and AFA by weight of total binder, %.

Table 9 The properties of air-entraining admixtures. Property

AEA1

AEA2

Main base

Synthetic surfactants 1.01 ± 0.02 8.8 60.1 61.0

Saponified acid resin 1.00 10–12 – –

Specific gravity at 20 °C (g/cm3) pH-value at 20 °C Chloride ion content (mass%) Alkali content (Na2O eqiv.) (mass%)

Symbol

SP1

SP2

AFA1

AFA3

AFA4

AFA5

AFA6

S1A1 S1A3 S1A4 S1A5 S1A6

2.40 4.23 3.67 5.20 3.67

– – – – –

3.61 – – – –

– 3.40 – – –

– – 3.48 – –

– – – 3.48 –

– – – – 4.06

S1A1 – SP1 + AFA1, S1A3 – SP1 + AFA3, S1A4 – SP1 + AFA4, S1A5 – SP1 + AFA5, S1A6 – SP1 + AFA6.

Table 15 The dosage of SP, AFA and VMA by weight of total binder, %.

Table 10 The properties of viscosity modifying admixtures. Property

VMA1

VMA2

VMA3

Main base

Synthetic copolymer 1.0–1.02

Silica

Methylcellulose

1.30

No data

6–9 <0.1 –

9.5 – –

– – –

Specific gravity at 20 °C (g/ cm3) pH-value at 20 °C Chloride ion content (mass%) Alkali content (Na2O eqiv.) (mass%)

Symbol

SP1

SP2

AFA1

AFA2

AFA3

VMA1

VMA2

VMA3

S1A1V1 S1A2V1 S1A3V1 S1A3V2 S1A1V2 S1A1V3

4.44 3.67 3.79 3.67 4.28 4.95

– – – – – –

3.50 – – – 3.45 4.07

– 3.45 – – – –

– – 3.45 3.45 – –

0.26 0.25 0.19 – – –

– – – 0.25 0.25 –

– – – – – 0.11

S1A1V1 – SP1 + AFA1 + VMA1, S1A2V1 – SP1 + AFA2 + VMA1, S1A3V1 – SP1 + AFA3 + VMA1, S1A3V2 – SP1 + AFA3 + VMA2, S1A1V2 – SP1 + AFA1 + VMA2, S1A1V3 – SP1 + AFA1 + VMA3.

Table 16 The dosage of SP and AEA by weight of total binder, %.

Table 11 The components of HPSCC.

Symbol

SP1

SP2

AEA1

AEA2

S2A1 S2A2

– –

4.49 3.16

0.27 –

– 1.58

S2A1 – SP2 + AEA1, S2A2 – SP2 + AEA2.

CEM I 42.5 R

Silica fume

Sand 0/2 (mm kg/m3)

Gravel 0/8 (mm)

Volume of paste (%)

w/c

w/b

581.0

65.0

710.1

887.6

40.0

0.31

0.28

fresh HPSCC. The slump flow test [4] was used to evaluate the free deformability and flowability of SCC. Slump flow value represented the mean diameter (measured in two perpendicular directions) of concrete after lifting the standard slump cone. The upper and lower limits of slump-flow classes (SF) are the following [4]: SF1 –

slump flow from 50 to 650 mm, SF2 – slump flow from 660 to 750 mm, SF3 – slump flow from 760 to 850 mm. While the upper and lower limits of viscosity classes (VS) are the following [4]: VS1 – T500 less than or equal to 2 s., VS2 – T500 higher than 2 s. The air content in fresh HPSCC was measured by the pressure method according to EN 12350-7 [24]. The results of measurements presented in Tables 18–23 were an average of three measurements and the results were corrected to take into account the aggregates.

B. Łaz´niewska-Piekarczyk / Construction and Building Materials 41 (2013) 109–124 Table 17 The dosage of SP, AEA and VMA by weight of total binder, %.

113

Table 19 Properties of fresh non-air-entrained HPSCC with different type of VMA.

Symbol

SP1

SP2

AEA1

AEA2

VMA1

VMA2

VMA3

S2A1V1 S2A1V2 S2A1V3 S2A2V1 S2A2V2

– – – – –

4.66 4.58 5.96 5.33 3.25

0.27 0.26 0.26 – –

– – – 0.91 1.32

0.27 – – 0.26 –

– 0.71 – – 0.71

– – 0.07 – –

S1A1V1 – SP1 + AEA1 + VMA1, S1A1V2 – SP1 + AEA1 + VMA2, S1A1V2 – SP1 + AEA1 + VMA3, S1A2V1 – SP1 + AEA2 + VMA1, S1A2V2 – SP1 + AEA2 + VMA2.

Symbol

SF (mm)

T500 (s)

Slump-flow classes

Viscosity classes

Ac (%)

S1V1 S2V1 S1V2 S2V2 S2V3 S1V3

650 730 770 640 580 680

4 3 4 4 7 8

SF1 SF2 SF3 SF1 SF1 SF2

VS2 VS2 VS2 VS2 VS2 VS2

2.4 1.8 2.7 1.9 3.6 2.6

S1V1 – SP1 + VMA1, S1V2 – SP1 + VMA2, S1V3 – SP1 + VMA3, S2V1 – SP2 + VMA1, S2V2 – SP2 + VMA2, S2V3 – SP2 + VMA3.

3.3.2. Tests on hardened HPSCC properties The temperature and relative humidity were respectively 20 °C and 100% (in water). After 28 days, the tests were conducted to determine the air-voids parameters of HPSCC. The entrained air void distribution in hardened concrete was determined using a computer-driven system of automatic image analysis (RapidAir). The RapidAir is an automatic system for analyzing the air void content of hardened concrete. The analysis requires polishing of the concrete surface as described in ASTM C 457 as well as a contrast enhancement of the surface. The system can automatically analyze the air void system according to the ASTM C 457 and EN 480-11 [25] standards. Tests were performed using polished concrete specimens 100  100  20 mm cut from cube specimens. The sample preparation includes contrast enhancement steps ensuring white air voids in black concrete (aggregate and paste). Because it performs the linear traverse method on a black and white surface the paste content cannot directly be measured. The software, however, has recently been updated to include an application for semi-automatic point count, where the paste content can be determined and used directly in the linear traverse analysis. Moreover the latest software has an integrated module for performing the air void analysis according to EN 480-11 modified point count Procedure B. Since neither of these new applications were available at the start of this study the paste content was determined manually by using EN 480-11 modified point count Procedure B and the automatic air void analysis by using the linear EN 480-11 Procedure A. Results of measurements were available as a set of standard parameters for the air void microstructure characterization: – – – – –

spacing factor (mm), specific surface a (1/mm), air content A (%), content of air voids with diameter less than 0.3 mm A300 (%), air void diameters distribution.

4. Test results and its discussion

Table 20 Properties of fresh non-air-entrained HPSCC with different type of AFA. Symbol

SF (mm)

T500 (s)

Slump-flow classes

Viscosity classes

Ac (%)

S1A1 S1A3 S1A4 S1A5 S1A6

690 670 850 630 600

3 4 2 6 3

SF2 SF2 SF3 SF1 SF1

VS2 VS2 VS1 VS2 VS2

2.5 2.4 2.0 2.9 2.9

S1A1 – SP1 + AFA1, S1A3 – SP1 + AFA3, S1A4 – SP1 + AFA4, S1A5 – SP1 + AFA5, S1A6 – SP1 + AFA6.

Table 21 Properties of fresh non-air-entrained HPSCC with different type of AFA and VMA. Symbol

SF (mm)

T500 (s)

Slump-flow classes

Viscosity classes

Ac (%)

S1A1V1 S1A2V1 S1A3V1 S1A3V2 S1A1V2 S1A1V3

700 650 730 790 730 500

4 5 6 4 5 9

SF2 SF1 SF2 SF3 SF2 SF1

VS2 VS2 VS2 VS2 VS2 VS2

2.4 3.9 2.7 1.2 2.3 4.9

S1A1V1 – SP1 + AFA1 + VMA1, S1A2V1 – SP1 + AFA2 + VMA1, S1A3V1 – SP1 + AFA3 + VMA1, S1A3V2 – SP1 + AFA3 + VMA2, S1A1V2 – SP1 + AFA1 + VMA2, S1A1V3 – SP1 + AFA1 + VMA3.

Table 22 Properties of fresh air-entrained HPSCC. Symbol

SF (mm)

T500 (s)

Slump-flow classes

Viscosity classes

Ac (%)

S2A1 S2A2

580 500

3 4

SF1 SF1

VS2 VS2

6.4 10.5

S2A1 – SP2 + AEA1, S2A2 – SP2 + AEA2.

4.1. The research results of fresh HPSCC Test results of the test of properties of the fresh modified HPSCC by admixtures are summarized in Tables 18–23. The Figs. 2–27 show the air void diameters distribution.

Table 18 Properties of fresh non-air-entrained HPSCC. Symbol

SF (mm)

T500 (s)

Slump-flow classes

Viscosity classes

Ac (%)

S1 S2

660 680

6 3

SF2 SF2

VS2 VS2

3.5 2.2

S1 – SP1, ‘‘air-entraining’’, S2 – SP2, ‘‘non-air-entraining’’.

Table 23 Properties of fresh air-entrained HPSCC with different type of VMA. Symbol

SF (mm)

T500 (s)

Slump-flow classes

Viscosity classes

Ac (%)

S2A1V1 S2A2V1 S2A2V2 S2A1V2 S2A1V3

570 630 570 530 500

4 5 4 5 10

SF1 SF1 SF1 SF1 SF1

VS2 VS2 VS2 VS2 VS2

5.2 3.5 9.0 9.5 7.0

S1A1V1 – SP1 + AEA1 + VMA1, S1A1V2 – SP1 + AEA1 + VMA2, S1A1V2 – SP1 + AEA1 + VMA3, S1A2V1 – SP1 + AEA2 + VMA1, S1A2V2 – SP1 + AEA2 + VMA2.

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The amount of admixtures (SP, VMA and AFA) according to their type was established iteratively in order to obtain the smallest air content and the biggest flow diameter of HPSCC. The relationship between the quantities of the various admixtures (according to Tables 11–16) and fresh-state results (according to Tables 17–22) depends on their type. Probably the interactions between admixtures cause different results in the flow properties and compaction of HPSCC. The analysis of the test results in Table 18 suggests that the type of the new generation SP influences essentially the air-content in the fresh high performance self-compacting concrete. SP1 increases the air content in HPSCC but less than that shown by the results of the research analyzed in the publication [12]. With increasing water content in the mixture, SP increases more the air-content in mixture. As it has been shown in the studies [12], the ‘‘air-entraining’’ SP1 is more effective in action (Table 12). On the other hand, the workability of HPSCC with, ‘‘non-air-entraining’’ SP2 is better (Table 18). The research results of the workability and air-content of HPSCC with VMA1, VMA2, and VMA3 are summarized in Table 19. The analysis of the results indicates that VMA (regardless of the VMA type) influences the air content in fresh HPSCC (compare Tables 18 and 19). VMA2 and VMA3 result in the decrease of the air-content in HPSCC with SP1. A different situation is the case of VMA3. Adding VMA3 to the HPSCC with SP2, results in a significant increase in the air content in HPSCC due to the increase of plastic viscosity (increase in T500) and yield stress (decrease of SF). Moreover, a combination of the type of SP and VMA is important because of HPSCC workability. The workability of S1V2 and S2V1 is better than workability of S1 and S2. While, workability of S1V1 and S2V2 is similar to the workability of S1 and S2 (compare Tables 18 and 19). The most beneficial to improve the workability is in case of HPSCC with SP2 and VMA3 (series S2V3). The most effective admixture is VMA3, and then respectively VMA1 and VMA2 (compare Table 13). The research results of the workability and air-content of HPSCC with different type of AFA are summarized in Table 20. The analysis of the results shows that the type of AFA is important both in terms of consistency and air content in HPSCC. The most beneficial effect in this regard is characterized by AFA4 (compare Tables 18 and 20). AFA4 causes the largest increase in diameter of the flow and reduce the air content in HPSCC. It should be noted that S1A4 is HPSCC but not fluid concrete. Probably interactions between SP1 and AFA4 are most beneficial to the workability of HPSCC. AFA6 has the least positive influence in this regard. On the other hand, the addition of AFA5 does not contribute to a reduction in time flow of HPSCC, as in case of AFA1, AFA3, AFA4 and AFA6. The least effective in action is AFA6 (compare Table 14). In Table 21, the research results of properties of HPSCC with AFA1, AFA2, AFA4 and VMA1, VMA2, VMA3 are summarized. The analysis of the results leads to the conclusion that the VMA causes various changes in HPSCC consistency, depending on both the AFA and VMA. The use of AFA3 with VMA2 is most suitable for workability and air content of HPSCC (compare Tables 20 and 21). The least favorable impact, as in case of S2V3 (Table 19), is characterized by VMA3. S1A1V3 has a SF of 500 mm and a T500 of 9 s and in Table 22 concrete S2A1V3 has a SF of 500 mm and a T500 of 10 s. These two last examples would not be classified as SCC. VMA3 (based on methylcellulose), increases the viscosity of nonair-entrained and air entrained SCC the most. VMA based on methylcellulose is not recommended to obtain good workability of HPSCC. Moreover, addition of VMA3 causes a significant increase of the air content in HPSCC (compare Tables 20 and 21). Test results of the properties of the air-entrained HPSCC are summarized in Table 22. As shown in Table 9, AEA1 source was a synthetic AEA detergent, whereas AEA2 sources was saponified

acid resin, which utilize different mechanisms to entrain air, and thus react differently with the other mixture constituents (i.e. cement, fly ash and admixtures) [26]. The analysis of the results suggests that the type of AEA is very important, because both of the consistency and the effect of the air entrainment of HPSCC. Research results [1], showed that the air void characteristics produced by the synthetic detergent AEA were more affected by increasing slump flow than produced by the salt-type AEAs. The air voids generated by salt-type AEAs are adhered to water-repellant precipitates (which are products of an immediate reaction between the AEA and calcium ions in concrete), resulting in similar air void characteristics regardless of slump flow [1,38]. As the research results of SCC [12] have shown, the air entrainment of HPSCC significantly reduces its diameter of flow. The flow time of the air-entrained HPSCC does not differ much from the flow time of the not air-entrained HPSCC, regardless of the AEA (compare Tables 18 and 22). The research results in Table 17 show that VMA1 is about 2.5 more efficient in action than VMA2. The test results of the properties of the air-entrained HPSCC with different type of VMA are summarized in Table 23. The results of the research carried out by Khayat [10], suggest an adverse effect of VMA on the air entrainment of concrete. The bubble-stabilizing capability of a synthetic detergent AEA is highly dependent on the amount of admixture in the bulk liquid phase [15]. The research results (Table 23) indicate that VMA1 decreases intentionally the air-entrainment (as a result of AEA1 and AEA2 acting) of the high performance self-compacting concrete mixture (compare Tables 22 and 23). The same amount of AEA1 in case of S2A and S2AV1 was used (Tables 16 and 17). VMA2 and VMA3 do not reduce the air entrainment of HPSCC. On the contrary, VMA3 and VMA2 cause an increase in entrainment of HPSCC with AEA1. VMA2 does not cause significant change in the air content of HPSCC with AEA2. In conclusion, the analysis of the results in Table 23 shows that the type of AEA and VMA influences the air entrainment and consistency of HPSCC. Lachemi et al. [27], indicted that the use of VMA leads to the reduction of the air content as a result of air-entraining admixture action in concrete, as it has been shown in Fig. 1. The results [28], seem to support this conclusion too. With an increased dosage of VMA, more water was absorbed, providing less free water for the AEA to bond with water, resulting in a greater demand of AEA to secure 6% air [28]. The analysis of the results indicates that VMA (regardless of the VMA type) influences the air content in fresh HPSCC. VMA2 and VMA3 result in the decrease of the air-content in HPSCC with SP1. A different situation is in case of VMA3. Adding VMA3 to the HPSCC with SP2 results in a significant increase in the air content in HPSCC due to the increase of plastic viscosity (increase in T500) and yield stress (decrease of SF). Moreover, a combination of SP and VMA types is important because of the HPSCC workability. The workability of S1V2 and S2V1 is better than workability of S1 and S2. While, the workability of S1V1 and S2V2 is similar to the workability of S1 and S2. The most beneficial to improve the workability is in case of SPSCC with SP2 and VMA3 (series S2V3). The most effective admixture is VMA3, and then respectively VMA1 and VMA2. Generally, the incorporation of a VMA can cause some delay in setting time because the VMA polymer chains can become adsorbed onto cement grains and interfere with the precipitation of various minerals into solutions that influence the rate of hydration and setting [29]. Author’s research results proved that VMA3 (based on methylcellulose) adversely affect the setting time of cement paste. HPSCC with VMA3 spent 24 h longer as compared to other types of VMA1 (based on synthetic copolymer) and VMA2 (based on silica). In general, mixtures incorporating a celluloseether-type VMA can exhibit some delay in setting time, and those made with acrylic-type VMAs do not delay the setting time [30].

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Table 27 The air-voids characteristics of non-air-entrained HPSCC with different type of AFA and VMA.

Fig. 1. Effect of VMA quantity on the air content of concrete [27]. A SP composed of naphthalene formaldehyde, VMA – polysaccharide-based admixture (suspension in water).

It was found that the rheological properties of the pastes are much more sensitive to SPs than VMAs [31]. This has been interpreted using the Krieger–Dougherty model for concentrated granular suspensions. In fact, this model indicates that rheological properties of the pastes would mainly depend upon the configuration of the granular skeleton and less on the fluid phase. The above result can then be understood since VMAs mainly affect the aqueous solution (by increasing it viscosity) while SPs can drastically change the granular phase configuration (dispersion of the flocs) [31]. 4.2. The research results of hardened HPSCC In Tables 24–29 and in Figs. 2–27, the air voids parameters research results are presented. The research results proved that admixture type is very important to the values of the HPSCC airvoids parameters.

Symbol

A (%)

a (mm 1)

L (mm)

A300 (%)

S1A1V1 S1A2V1 S1A3V1 S1A3V2 S1A1V2 S1A1V3

2.14 2.82 1.46 0.88 1.88 3.48

13.15 15.28 11.49 16.81 11.37 14.44

0.640 0.427 0.890 0.770 0.790 0.411

0.20 0.70 0.16 0.18 0.24 0.80

S1A1V1 – SP1 + AFA1 + VMA1, S1A2V1 – SP1 + AFA2 + VMA1, S1A3V1 – SP1 + AFA3 + VMA1, S1A3V2 – SP1 + AFA3 + VMA2, S1A1V2 – SP1 + AFA1 + VMA2, S1A1V3 – SP1 + AFA1 + VMA3.

Table 28 The air-voids characteristics of air-entrained HPSCC. Symbol

A (%)

a (mm 1)

L (mm)

A300 (%)

S2A1 S2A2

6.37 8.18

31.02 28.63

0.16 0.16

4.54 3.85

S2A1 – SP2 + AEA1, S2A2 – SP2 + AEA2.

Table 29 The air-voids characteristics of air-entrained HPSCC with different type of VMA. Symbol

A (%)

a (mm 1)

L (mm)

A300 (%)

S2A1V1 S2A2V1 S2A2V2 S2 A1V2 S2A1V3

5.97 2.57 6.36 6.10 7.17

24.67 8.52 22.26 32.01 26.11

0.210 0.798 0.203 0.170 0.164

2.83 0.33 2.26 4.26 4.26

S1A1V1 – SP1 + AEA1 + VMA1, S1A1V2 – SP1 + AEA1 + VMA2, S1A1V2 – SP1 + AEA1 + VMA3, S1A2V1 – SP1 + AEA2 + VMA1, S1A2V2 – SP1 + AEA2 + VMA2. Table 24 The air-voids characteristics of non-air-entrained HPSCC. Symbol

A (%)

a (mm 1)

L (mm)

A300 (%)

S1 S2

3.69 2.23

14.99 8.74

0.44 0.93

0.85 0.16

S1 – SP1, ‘‘air-entraining’’, S2 – SP2, ‘‘non-air-entraining’’.

Table 25 The air-voids characteristics of non-air-entrained HPSCC with different type of VMA. Symbol

A (%)

a (mm 1)

L (mm)

A300 (%)

S1V1 S2V1 S1V2 S2V2 S2V3 S1V3

2.53 2.66 1.36 1.68 2.18 3.00

18.03 11.21 14.52 10.23 19.27 9.51

0.430 0.670 0.720 0.920 0.379 0.667

0.87 0.36 0.09 0.15 0.75 0.37

S1V1 – SP1 + VMA1, S1V2 – SP1 + VMA2, S1V3 – SP1 + VMA3, S2V1 – SP2 + VMA1, S2V2 – SP2 + VMA2, S2V3 – SP2 + VMA3.

Table 26 The air-voids characteristics of non-air-entrained HPSCC with different type of AFA. Symbol

A (%)

a (mm 1)

L (mm)

A300 (%)

S1 S1A1 S1A3 S1A4 S1A5 S1A6

3.69 2.99 2.37 1.96 1.75 2.45

14.99 9.34 9.32 15.53 16.10 11.30

0.440 0.770 0.890 0.493 0.500 0.614

0.85 0.25 0.16 0.42 0.56 0.58

S1A1 – SP1 + AFA1, S1A3 – SP1 + AFA3, S1A4 – SP1 + AFA4, S1A5 – SP1 + AFA5, S1A6 – SP1 + AFA6.

The analysis of the results summarized in Table 24 leads to the conclusion that the type of SP is very important because of the parameters values of the HPSCC air voids. The characteristics of HPSCC porosity is shown in Figs. 2 and 3. The air voids diameters distribution in S2 also show the significance of the SP type impact. SP1 increases the air content in HPSCC but less than that shown by the results of the research analyzed in the publication [12]. With increasing water content in the mixture, SP increases the air-content in mixture more. As it has been shown in the studies [12], the ‘‘air-entraining’’ SP1 is more effective in action. On the other hand, the workability of HPSCC with, ‘‘non-air-entraining’’ SP2 is better. The molecules of SP should also modify the surface of solid particles in order to keep its hydrophilic character. The air bubbles can adhere only to hydrophobic surfaces. The presence of listed functional groups (oxygen in the form of etheric group (–0–), hydroxyl group (–OH) and carboxyl group) produce water surface tension decrease, producing flocculation of associated molecules and increase in moisture of not only grains of cement but also the whole mineral framework [32]. The results [33] proved that some type of SP air-entrains the concrete mixture by reducing the surface tension of the liquid phase in paste. However, in the SPs group there are ones that show only dispersion functioning not decreasing surface tension. They are: hydrocarboxylen acid salts, sulphonic melamine-formaldehygenic resins and formaldehygenic picodensats salts of beta-naphthalenesulphonic acid [34]. According to [6], the type of SP is crucial regarding the size and proportions of air pores participation, obtained as a result of its functioning, although the time of hardening of concrete does make a difference to further changes of these proportions. With the use of polycarboxylen SPs, air pores are characterized by diameters smaller than in case of

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Fig. 2. The air voids diameters distribution in S1.

Fig. 3. The air voids diameters distribution in S2.

Fig. 4. The air voids diameters distribution in S1V.

pores formed as a result of the functioning of lingosulphonic or naphthalene SPs. Many studies have been carried out on the fluidizing mechanisms of these admixtures in cement paste, and some theories have been used to explain the mechanisms by which these admixtures interact with cement particles, such as the DLVO Theory, the Steric Effect Theory, the Depletion Effect Theory and the Tribology Effect [35]. However, when systems contain blended ternary cement in the presence of SP combined with VMA like the most formulations of SCC, it becomes more difficult to predict the evolution of the systems and to explain the mechanisms of the resulting interactions [36]. The research results of the air voids characteristics of HPSCC with VMA1, VMA2, VMA3 are summarized in Table 25. The analysis of the results suggests that the type of VMA is very important due to the size of the air voids parameters of HPSCC. The type of SP is also important because of the influence of VMA in this regard. The use of VMA leads to the reduction of the air content in concrete according to research results [8,10,27]. However, the research results in Table 25 show that the parameters of the HPSCC air voids are characterized by very different values, depending on what type of SP and VMA was used. Comparing the porosity parameters of HPSCC with SP1 and the different types of VMA (S1V1, S1V2 and

S1V3), it appears that the VMA2 causes the greatest reduction in the air content in HPSCC (Fig. 6). VMA2 increases the size of the air voids spacing factor and decreases the content of voids smaller than 300 lm (Table 25). VMA1 (based on synthetic copolymer) does not cause significant changes in parameters of the air voids, in addition to the total of their contents. VMA3 (based on methylcellulose) does not cause a significant reduction in the air content of HPSCC. However, the research results summarized in Table 25 and in Fig. 9 show that the pores are characterized by larger diameters (compare S1 and S1V3). The addition of VMA to HPSCC with SP2 also changes the parameters of the air voids size, smaller or larger, depending on the type of VMA. VMA3 (based on methylcellulose) causes the greatest change in pore size (Fig. 8). Furthermore, the air voids spacing factor is reduced almost three times. The specific surface of the voids is reduced more than doubled (compare S2 and S2V3, Table 25). The greatest reduction in porosity causes VMA2 (based on silica), as in case of HPSCC with SP1 (Fig. 7). The research results of the air-voids characteristics of HPSCC with AFA1, AFA2 and AFA3 are shown in Table 26. The analysis of the results proves that the type of AFA is important because of the value of the parameters of the air voids in HPSCC. The most effective admixture in reducing the air content in HPSCC is AFA5,

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Fig. 5. The air voids diameters distribution in S2V.

Fig. 6. The air voids diameters distribution in S1V2.

Fig. 7. The air voids diameters distribution in S2V2.

Fig. 8. The air voids diameters distribution in S2V3.

and the least efficient, AFA1 (compare Figs. 2, 10 and 13). The greatest increase in the air voids diameters is in case of HPSCC with AFA3 (compare Figs. 2 and 11 and Table 26). Table 27 shows the research results of HPSCC porosity characteristics with AFA1, AFA2, AFA4 and VMA1, VMA2, VMA3. The analysis of the results suggests that the type of AFA and VMA is

important because of the porosity of HPSCC. VMA1 and VMA2 decrease the air voids content in HPSCC with AFA1, whereas VMA3 increases the air voids content, especially with a diameter of 0.5 mm (compare Tables 26 and 27, Figs. 19 and 20). VMA2 causes greater reduction in porosity than VMA1 in case of HPSCC with AFA3 (Fig. 18, and Tables 26 and 27).

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Fig. 9. The air voids diameters distribution in S1V3.

Fig. 10. The air voids diameters distribution in S1A1.

Fig. 11. The air voids diameters distribution in S1A3.

Fig. 12. The air voids diameters distribution in S1A4.

Both the AEA and polycarboxylate-ester SP1 and SP2 are surfactants, relying on adsorption to the cement particles to both stabilize air bubbles and to fluidize the cement paste [1]. Therefore, the increased dosage of SP at the higher slump flows competed with the AEA for adsorption to the cement surface area, resulting in a poorer air void system [14]. Additionally, synthetic detergent

AEAs are influenced by increased fluidity due to their primary location at the air–water interface [15]. The results of the determination of the air voids parameters of the air-entrained HPSCC are summarized in Table 28. AEA2 has a smaller efficiency than AEA1 (Table 16). While these air voids have been known to adsorb to cement particles, the analysis of the results in Table 28 shows

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Fig. 13. The air voids diameters distribution in S1A5.

Fig. 14. The air voids diameters distribution in S1A6.

Fig. 15. The air voids diameters distribution in S1A1V1.

Fig. 16. The air voids diameters distribution in S1A2V1.

that the type of AEA is very important because of the air content in HPSCC. AEA1 source produced the smallest and most closely spaced air voids, followed by AEA2 sources. Other parameters of porosity of HPSCC with AEA 1 and AEA2 are similar. However, the air voids have a smaller diameter in case of HPSCC with AEA1 (compare Figs. 21 and 22). The bubbles created by AEA1 source were more likely to coalesce than the bubbles produced

by salt-type AEAs [37]. Salt-type AEAs react immediately with the ions in cement pastes, creating insoluble water-repellant precipitates that, when caught in water–air interfaces, tend to remain partially dry [37]. The salt-type AEAs tended to develop mid-size bubbles, which are reflected in the moderate air void generated characteristics. In contrast, synthetic detergents AEAs are pure surfactants that are form a film at the air–water and air–water–ce-

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Fig. 17. The air voids diameters distribution in S1A3V1.

Fig. 18. The air voids diameters distribution in S1A3V2.

Fig. 19. The air voids diameters distribution in S1A1V2.

Fig. 20. The air voids diameters distribution in S1A1V3.

ment interfaces and reduce the surface tension of water [37]. The reduction of surface tension of water prevents the air voids from coalescing into larger air voids through the combined Gibbs– Marangoni effect, thus stabilizing them throughout the fresh concrete [15].

The research results in Table 28 proved that higher air content does not improve the air-void factor of concrete. This confirms the observation by Plante, Pigeon and Foy that increased air content is not necessarily representative of improved air void characteristics [17].

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Fig. 21. The air voids diameters distribution in S2A1.

Fig. 22. The air voids diameters distribution in S2A2.

Fig. 23. The air voids diameters distribution in S2A1V1.

Fig. 24. The air voids diameters distribution in S2A2V1.

Increasing fluidity generally increased the required AEA dosage, other factors such as AEA type, and SP and VMA amount also played a role in determining AEA dosage. The common VMAs in concrete include microbial polysaccharides (such as Welan gum),

cellulose derivatives (methyl cellulose), and acrylic polymers [39,40]. The mechanism of action in each case is different. Some VMAs adsorb on cement particles and increase viscosity by promoting inter-particle attraction [22,27,41,42]. The VMAs can re-

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Fig. 25. The air voids diameters distribution in S2A2V2.

Fig. 26. The air voids diameters distribution in S2A1V2.

Fig. 27. The air voids diameters distribution in S2A1V3.

Fig. 28. The relationships between the air-content in fresh and in hardened non-air-entrained HPSCC.

duce the ability of the air-entraining admixture (AEA) to create a proper air void system. Research results [10,27] proved that VMA influences the air-content in SCC. The research results [27] indicated that the air content seems to decrease with the increase of VMA content in the SCC mixes. This suggests that the incorporation of VMA will probably need? greater additions of the air entraining agents to secure a given air volume. The usage of admixtures such

as VMA and SP can reduce the ability of the air-entraining admixture (AEA) to create a proper air void system [14]. The other admixtures can interfere with the ability of AEA to stabilize air voids in concrete in a way in which they interact on a molecular level [14]. The research results of the porosity characteristics of the air-entrained HPSCC with VMA1, VMA2 and VMA3 are summarized in Table 29. The analysis of the results shows that VMA,

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Fig. 29. The relationships between the air-content in fresh and in hardened air-entrained HPSCC.

depending on its type, is reducing or increasing the air content in HPSCC. The bubble-stabilizing capability of a synthetic detergent AEA is highly dependent on the amount of admixture in the bulk liquid phase [15]. VMA reduced the free water content, thus needing? increased amounts of the synthetic detergent AEA to entrain the same amount of the air. VMA2 causes the smallest change in the values of the air voids parameters of HPSCC with AEA1. Also in case of HPSCC with VMA2 and AEA2 the porosity parameters are similar to the air voids parameters of HPSCC without VMA2. VMA1 adversely affects the HPSCC air entrainment (Fig. 24). VMA3 causes an increase in the content of the air pores in HPSCC, while the remaining porosity parameters are not significantly changed (Fig. 27). Therefore, from the viewpoint of the frost resistance of HPSCC, the use of VMA3 seems to be the most beneficial (compare Tables 28 and 29). Many factors influence the air-voids stability in concrete [43]. The relationships between the measurements of the total volume of fresh and hardened air content was reported by several researchers. The comparison of data in Figs. 28 and 29 suggests that it is not possible to predict the air-content in non-air-entrained HPSCC on the basis of the air-content in high performance self-compacting concrete mixture. However, there are no significant differences between the air-content in fresh and in hardened air-entrained HPSCC. It indicates that the air-content in non-airentrained HPSCC is more unstable than the air entrainment from the AEA action. 5. Conclusions In the range of investigation of the HPSCC, used admixtures and received research results it was indicated that the examined admixtures significantly affect the properties of fresh and hardened non-air-entrained and air-entrained HPSCC. The research results of the admixtures influence the HPSCC properties, proved that:  The type of SP is very important because of the parameters size of HPSCC air pores. In case of HPSCC with ‘‘air-entraining’’ SP, the content of the air pores is higher only by 1.46%, but the specific surface of the air voids, air voids spacing factor and content of the air voids with diameters less than 300 lm are much higher.  The type of SP, VMA are important because of the workability of the HPSCC. In addition, each of the analyzed admixtures has a very different efficiency in action. The VMA type also affects very significantly the content of the air in HPSCC. One type of VMA reduces the air content in HPSCC, while another type of VMA increases the air content in HPSCC. The type of VMA is very important because of the parameters size of HPSCC air voids. The influence of VMA also depends on the type of SP used in HPSCC. The parameters of HPSCC air voids are characterized by very different values, depending on what kind of SP and VMA was used. Depending on the type of SP, the effect of the impact of the type of VMA is smaller or higher.

 The effects of modification by AFA of HPSCC depend on their type very significantly. The type of AFA impacts very significantly on the air content and workability of HPSCC. In case of one AFA type, it is significant increase in diameter of flow while reducing the air content in HPSCC. Other type of AFA does not improve the workability and does not cause a significant reduction in the air content in HPSCC. The type of AFA is also important because of the parameters values of the air voids of HPSCC. Depending on the type of AFA, the change of the size and content of pores in HPSCC differs.  VMA, depending on the type of AFA and VMA, has more or less beneficial effect on the air content in HPSCC. The use of one type of VMA does not increase the air content in HPSCC with AFA. Another type of VMA significantly increases the air content in HPSCC with AFA. VMA affects the air content in HPSCC, also depends on the type of AFA. Depending on the type of VMA and AFA, a very different change in the characteristics of the air voids is observed. In one case, VMA does not change the characteristics of the porosity, in the second, significantly affects.  The type of AEA is very important due to the efficiency. The analysis of the results shows that the type of AEA significantly affects the total air content in hardened HPSCC. Other parameters of HPSCC porosity, with different types of AEA, are similar. However, depending on AFA type, more or less frequently there are the smallest air voids.  The effect of VMA on the air entrainment of HPSCC depends on VMA type very significantly. One type of VMA reduces the airentrainment of HPSCC. Another type of VMA contributes to increasing the air-entrainment of HPSCC. Moreover, the impact of VMA air-entrainment also depends on the type of AEA. VMA causes a reduction in the air-entrainment of HPSCC with some types of AEA. In case of other types of AEA, the same kind of VMA does not adversely affect the HPSCC air-entrainment. The parameters values of the air voids also depend on the type of AEA and VMA. Some types of VMA affect the values of the air voids very adversely. References [1] Barfield M, Ghafoori N. Air-entrained self-consolidating concrete: a study of admixture sources. Constr Build Mater 2012;26:490–6. [2] MacInnis C, Racic D. The effect of SPs on the entrained air-void system in concrete. Cem Concr Res 1986;16(3):345–52. [3] Szwabowski J, Łaz´niewska-Piekarczyk B. The increase of air-content in mix under influence of carboxylate SPs acting. Cem Wapno Beton 2008;4:205–15. [4] EN 12350-8:2010, Testing fresh concrete – Part 8: self-compacting concrete – slump-flow test. [5] Hanehara S, Yamada K. Rheology and early age properties of cement systems. Cem Concr Res 2008;21:175–95. [6] Sakai E, Kasuga T, Sugiyama T, Asaga K, Daimon M. Influence of SPs on the hydration of cement and the pore structure of hardened cement. Cem Concr Res 2006;36:2049–53. [7] Khatib JM, Mangat PS. Influence of SP and curing on porosity and pore structure of cement paste. Cem Concr Compos 1999;21:431–7. [8] Łaz´niewska-Piekarczyk B. The influence of selected new generation admixtures on the workability, air-voids parameters and frost-resistance of SCC. Constr Build Mater 2012;31:310–9.

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