Effect of polyacrylic acid emulsion on fluidity of cement paste

Guo, Yanfei; Ma, Baoguo; Zhi, Zhenzhen; Tan, Hongbo; Liu, Muyu; Jian, Shouwei; Guo, Yulin

doi:10.1016/j.colsurfa.2017.09.039

Cited by 58 publications

(13 citation statements)

References 33 publications

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“…With the addition of CH into polymer solutions, the size distribution of polymers for PAA3 and PAA50 is about 161–396 nm and 191–458 nm. In the presence of Ca 2+ , PAA molecule might be curled because of the combination of Ca 2 and the formation of hydrogen bond; it could be deduced that several carboxyl groups (COO − ) from different PAA molecules could be connected with one Ca 2+ , and several carboxyl groups (COO − ) in one PAA molecule could also be connected with one Ca 2+ [ 4 , 5 ]. In this case, the conformation behavior of PAA would be altered in cement suspension.…”

Section: Resultsmentioning

confidence: 99%

“…Generally, this can be obtained with addition of viscosity-enhancing agent (VEA) and superplasticizer [ 1 , 2 , 3 ]. Polyacrylic acid (PAA) is one of the most commonly used viscosity-enhancing agents with an excellent effect on resisting bleeding and segregation [ 4 , 5 ]. The primary mechanism behind includes two aspects: one is that it can increase viscosity of liquid phase by means of the formation of intermolecular network structure, and the other is that PAA molecule with great molecular weight can connect these cement particles through adsorbing on the surface of cement particles [ 6 , 7 ].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Polyacrylic Acid on Rheology of Cement Paste Plasticized by Polycarboxylate Superplasticizer

Peng

Tan

et al. 2018

Materials

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Viscosity-enhancing agents (VEA) have been widely employed in high flowability cement-based materials, so as to ensure that no bleeding and segregation would occur. However, in most cases, interaction between VEA and superplasticizer would be unavoidable. In this study, the effect of polyacrylic acid (PAA), known as one of the most commonly used VEAs, on rheology performance of cement paste containing polycarboxylate superplasticizer (PCE), was studied. The initial fluidity was assessed with mini slump, and rheological behavior of cement paste was evaluated with rotor rheometer. Adsorption amount was examined with total organic carbon (TOC) analyzer, and the zeta potential was also tested. The interaction between PAA and PCE in the presence of calcium ion (Ca2+) was analyzed with conductivity, X-ray photoelectron spectroscope (XPS), and dynamic light scattering (DLS). The results illustrate that PAA can adsorb onto the surface of cement particles to plasticize cement paste, being similar to PCE. In the presence of Ca2+, PAA can be curled and crosslinked, as a result of the combination between carboxyl groups (COO−) and Ca2+, thereby affecting the adsorption performance and conformation behavior. It is interesting that negative impact of PAA on dispersion efficiency of PCE can be demonstrated; one reason is the reduced adsorption amount of PCE by PAA competitively adsorbing onto the cement surface, and another possible reason is the invalided PCE by adsorption of PAA. Additionally, molecular weight of PAA should be considered if being used as VEA in PCE system.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Polyacrylic Acid on Rheology of Cement Paste Plasticized by Polycarboxylate Superplasticizer

Peng

Tan

et al. 2018

Materials

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“…In order to meet the requirements of rapid open traffic, the emulsifier used in the micro-surface must be slow-breaking and quick-curing cationic emulsifier. The commonly used modifiers are styrene–butadiene–styrene (SBS), styrene–butadiene rubber (SBR), and chloroprene rubber (CR) [ 32 ].…”

Section: Materials and Research Methodologiesmentioning

confidence: 99%

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing

et al. 2018

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Micro-surfacing is a widely used pavement preventive maintenance technology used all over the world, due to its advantages of fast construction, low maintenance cost, good waterproofness, and skid-resistance performance. This study evaluated the fine aggregate morphology and surface texture of micro-surfacing by AIMS (aggregate image measurement system), and explored the effect of aggregate morphology on skid-resistance of single-grade micro-surfacing. Sand patch test and British pendulum test were also used to detect skid-resistance for comparison with the image-based method. Wet abrasion test was used to measure skid-resistance durability for feasibility verification of single-grade micro-surfacing. The results show that the effect of Form2D on the skid-resistance of micro-surfacing is much stronger than that of angularity. Combining the feasibility analysis of durability and skid-resistance, 1.18–2.36 grade micro-surfacing meets the requirements of durability and skid-resistance at the same time. This study also determined that, compared with British pendulum test, the texture result obtained by sand patch test fits better with results of image method.

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“…Therefore, the reason why the poly-phosphate could effectively enhance the dispersion, whilst the mono-phosphate failed cannot be simply explained by the retarding effect. One possible explanation might be attributed to the difference in the molecular structure of the phosphates, which could result in different performance at the water/solid interface during the very early-stage hydration [39][40][41][42], and this would further influence the adsorption layer [43][44][45]. As a consequence, the difference in PCE adsorption behavior could be expected in the presence of different phosphates.In this study, the dispersion mechanism of the PCE-phosphate system was investigated.…”

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confidence: 99%

Effect of Sodium Hexametaphosphate and Trisodium Phosphate on Dispersion of Polycarboxylate Superplasticizer

Zhang

Liu

et al. 2019

Materials

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Enhancement in dispersion of polycarboxylate superplasticizer (PCE) could be obtained by incorporating retarders in normal concrete. The generally believed reason was that the consumption of free water and polymer at the beginning was reduced by retarding cement hydration. This theory could not convincingly explain why sodium hexametaphosphate (SHMP) was able to promote the dispersion capacity of PCE, while trisodium phosphate (TSP) could not, despite that both TSP and SHMP could obviously retard the cement hydration. The adsorption behavior of PCE and phosphate was investigated and the mechanism was analyzed in order to gain deeper understanding. The results showed that TSP and SHMP delayed the cement hydration, impeded adsorption process of PCE, and increased thickness of adsorption layer. It was interesting that TSP reduced the dispersion, but SHMP enhanced. The reason for this contradiction was due to the difference in composition of adsorption layer. In the PCE-TSP system, this layer was composed of the precipitates (formed by TSP and Ca 2+ ) and the invalided PCE (caused by these precipitates in the immediate vicinity of the cement grains); the invalided PCE was due to the decrease of PCE dispersion. In the PCE-SHMP system, "Inner-phosphate (multi-layers) + Outer-PCE (single layer)" structure was formed to make the PCE work more effective, hence enhancing the dispersion. These results were expected to be useful for the design of highly efficient dispersants. dispersion capacity [26][27][28][29][30]. Based on this, the retarder might hinder the adsorption process of PCE and it was referred to as competitive adsorption [31][32][33][34][35], thereby reducing the dispersion. In addition, the thickness of the adsorption layer should also be accepted as a factor influencing the dispersion of PCE [36,37]. In spite of the decline in adsorption amount of PCE in the presence of retarder, as reported in previous study, the adsorption layer was obviously thickened to enhance the dispersion [37]. On the basis of discussion above, the conclusion could be made that the dispersion capacity of the PCE-retarder system should be associated with the retarding effect of retarder, adsorption behavior of PCE, and the thickness of the adsorption layer.Poly-phosphates, such as sodium tripolyphosphate and sodium hexametaphosphate (SHMP), have been widely used to promote the dispersion ability and dispersion retention ability of the superplasticizer system in real engineering practice. However, mono-phosphates, such as trisodium phosphate (TSP) and sodium hydrogen phosphate, cannot play the same roles as poly-phosphate in commercially available PCE products. If the retardation was the main reason for the enhancement, poly-phosphate and mono-phosphate would both have a similar effect on dispersion of PCE system, because both TPS and SHMP could retard the cement hydration [38]. Therefore, the reason why the poly-phosphate could effectively enhance the dispersion, whilst the mono-phosphate failed cannot be simply explained by the retard...

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Effect of polyacrylic acid emulsion on fluidity of cement paste

Cited by 58 publications

References 33 publications

Effect of Polyacrylic Acid on Rheology of Cement Paste Plasticized by Polycarboxylate Superplasticizer

Effect of Polyacrylic Acid on Rheology of Cement Paste Plasticized by Polycarboxylate Superplasticizer

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing

Effect of Sodium Hexametaphosphate and Trisodium Phosphate on Dispersion of Polycarboxylate Superplasticizer

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