Effect of sodium tripolyphosphate on adsorbing behavior of polycarboxylate superplasticizer

Tan, Hongbo; Zou, Fubing; Ma, Baoguo; Liu, Min; Li, Xin; Jian, Shouwei

doi:10.1016/j.conbuildmat.2016.09.077

Cited by 52 publications

(19 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…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].…”

mentioning

confidence: 73%

“…Based on this, the thickness of adsorption layer could be calculated from the XPS data of silicon [37].…”

Section: Pce (G/l) Tsp (G/l) Shmp (G/l)mentioning

confidence: 99%

“…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.…”

mentioning

confidence: 99%

See 2 more Smart Citations

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

Zhang

Liu

et al. 2019

Materials

View full text Add to dashboard Cite

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...

show abstract

mentioning

confidence: 73%

“…Based on this, the thickness of adsorption layer could be calculated from the XPS data of silicon [37].…”

Section: Pce (G/l) Tsp (G/l) Shmp (G/l)mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

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

Zhang

Liu

et al. 2019

Materials

View full text Add to dashboard Cite

show abstract

“…The PCE has unparallel advantages in improving concrete performances compared to traditional water reducer such as naphthalene sulfonate and melamine sulfonate. However, the common PCE has strong retardation effect on cement hydration process in concrete system, and results in slower growth of the early‐strength of concrete . In modern construction industry, precast concrete units are frequently applied to construction engineering field such as subway segments, railway box beams, prefabricated housing components, and pavement quick service.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a novel early‐strength polycarboxylate superplasticizer and its performances in cementitious system

Xia

Zhou

Ni³

et al. 2020

J of Applied Polymer Sci

View full text Add to dashboard Cite

A novel early-strength type polycarboxylate superplasticizer (PCE) was synthesized by a new design of molecule structure such as introducing long polyoxyethlene side chains, functional monomer (2-acrylamide-2-methylpropanesulfonic acid), and optimizing monomer composition. In this study, with introducing the sulfonate groups into PCE structure, its dispersion capacity and the absorbed amount are increased firstly and then decreased, but the retardation hydration effect is weakened gradually. The molecular weight, adsorbed amount, and dispersion capacity of PCEs firstly increased and then decreased with increasing the AA/TPEG monomer molar ratio, and the same trend as the compressive strength harden concrete with PCEs at the age of 1, 3, and 28 days. The early-strength type PCE exhibits good dispersive capacity and weak retardation hydration effect in cementitious system, and the early age strength of concrete with addition of early-strength type PCE develops quickly. This study indicates that reasonable design of PCE molecule structure and synthesis method can obtain a novel early-strength type PCE which makes a good balance between workability and fast development of early age strength in cementitious system.

show abstract

“…The research direction is whether there are other new types of molecular structure contributing to higher effectiveness. Current researches on the molecular design of PCEs has mainly focus on traditional comb‐shaped structure but scarcely on star‐shaped structure. Star‐shaped polymers could have a different molecular topological structure contributing to PCEs' dispersion effect and other cement workability.…”

Section: Introductionmentioning

confidence: 99%

Regulating the arm structure of star‐shaped polycarboxylate superplasticizers as a means to enhance cement paste workability

Zhao

Nian

Pang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

Star-shaped superplasticizers, which incorporated polyol ester with unsaturated bond at their cores and bore comb-type structures as their arms were synthesized via esterification-copolymerization in aqueous phase from pentaerythritol, acrylic acid (AA), and isopentenyl oxy poly(ethylene glycol ether) (TPEG). The monomer ratios of AA and TPEG were varied and comonomer sodium methallyl sulfonate (SMAS) bearing short side chains was added to regulate the arm structure of star-shaped polycarboxylate superplasticizers (SPCEs). The effects of the SPCEs on cement paste were investigated and the cement dispersion as well as early hydration mechanism were explored. As a main result, SPCEs with SMAS and certain molar ratios for anchoring groups and PEO side-chains in their arm structure exhibited good paste dispersion and fluidity retention, which also delayed the early hydration process and prolonged both the initial and the final setting time.

show abstract

Effect of sodium tripolyphosphate on adsorbing behavior of polycarboxylate superplasticizer

Cited by 52 publications

References 29 publications

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

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

Synthesis and characterization of a novel early‐strength polycarboxylate superplasticizer and its performances in cementitious system

Regulating the arm structure of star‐shaped polycarboxylate superplasticizers as a means to enhance cement paste workability

Contact Info

Product

Resources

About