Less Loss of Fluidity of Polycarboxylic Acid Type Water Reducer

2011 ◽  
Vol 71-78 ◽  
pp. 3452-3456
Author(s):  
Xun Zhong
Keyword(s):  
Molecular Weight ◽  
Cement Paste ◽  
Side Chain ◽  
Polycarboxylic Acid ◽  
Acid Type ◽  
Type Water ◽  
Different Molecular Weight

Cement paste and concrete with different molecular weight of side-chain of polycarboxylic acid type water reducer (PC) and retarder has been researched. In this way, the method of adjusting the molecular weight of side-chain and complexing retarder to hold fluidity has been discussed. The results show that with increase molecular weight of side-chain, the dispersibility and holding dispersibility increases. With retarder and PC, the dispersibility and holding dispersibility of PC with big more molecular weight of side-chain increases and the loss of fluidity at 1h prominence reduces. But it relates to breed of cement. Especially at low ratio of water and cement, when molecular weight of side-chain is more than 2000, complexing PC and retarder can improve the fluidity and holding fluidity.

Effect of Molecular Weight of Long-Side-Chain of Polycarboxylic Acid Type Water-Reducer on Hydration of C3A

2011 ◽  
Vol 71-78 ◽  
pp. 250-256 ◽  
Author(s):  
Hong Bo Tan ◽  
Bao Guo Ma ◽  
Kai Ke ◽  
Jun Xiao
Keyword(s):  
Molecular Weight ◽  
Chain Structure ◽  
Reducing Agents ◽  
Side Chain ◽  
Polycarboxylic Acid ◽  
Acid Type ◽  
Hydrated Products ◽  
Type Water

Several polycarboxylic acid type water-reducing agents (PCs) with different side-chain structure have been synthesized. The effect of side-chain structure of PCs on hydration of C3A has been investigated by XRD, TG-DSC and SEM. The results show that PCs restrain hydration of C3A as a whole, but accelerate the transformation from C2AH8 to Al (OH) 3 and C3AH6; for structure of the PCs, the bigger molecular weight of long-side-chain of PCs is advantage to restrain hydration of C3A. And it also is better to formation of six-party flake hydrated products. But the little molecular weight of long-side-chain of PCs tends to form the cube-shaped hydrated products.

Effect of Side-Chain Structure of Polycarboxylic Acid Type Water-Reducer on Hydration of C3A

2012 ◽  
Vol 550-553 ◽  
pp. 807-812 ◽  
Author(s):  
Yan Chao Zhu ◽  
Bao Guo Ma ◽  
Hong Bo Tan
Keyword(s):  
Molecular Weight ◽  
Chain Structure ◽  
Side Chain ◽  
Polycarboxylic Acid ◽  
Acid Type ◽  
Hydrated Products ◽  
Type Water

Several polycarboxylate superplasticizers (PCs) with different side-chain structure have been synthesized. The effect of side-chain structure of PCs on hydration of C3A has been investigated by XRD, TG-DSC and SEM. The results show that PCs restrain hydration of C3A as a whole, but accelerate formation of Al(OH)3 and C3AH6; with increase molecular weight of long-side-chain, hydration of C3A is slowed, and the formation of Al (OH)3 and C2AH8 also become slowed. With increase proportion of long-side-chain, hydration of C3A and formation of C3AH6 are slowed, but existence of C2AH8 become obvious. The six-party flake hydrated products of C3AH6 are formed with a large number of grafted carboxyl.

scholarly journals Research and Application of Polycarboxylic Acid Water Reducer with Different Molecular Weight

2020 ◽  
Vol 179 ◽  
pp. 01021
Author(s):  
Bobo Liu ◽  
Kangjian Yu ◽  
Yinggang Yang ◽  
Donghui Miao ◽  
Chong He
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Reducing Agent ◽  
Acid Water ◽  
Low Molecular Weight ◽  
High Grade ◽  
Polycarboxylic Acid ◽  
Different Molecular Weight

In this paper, a polycarboxylic water reducing agent was synthesized by using Methylallyl polyethylene glycol (HPEG) with molecular weight of 1200, 2400, 2800 and 3400 under the same conditions, C80 concrete tests were performed on these four molecular weight superplasticizers, verify the effect of different molecular weight polycarboxylic acid water reducer in C80 pumping concrete, finally, a kind of low molecular weight polycarboxylic acid water reducer with viscosity reducing effect in high-grade concrete is obtained, which can promote pumping of high-grade concrete.

scholarly journals Study on adsorption, rheology and hydration behaviours of Polycarboxylate(PCE) superplasticizer synthesized by different acid to ether ratio

2021 ◽  
Vol 2133 (1) ◽  
pp. 012007
Author(s):  
Zhijun Lin ◽  
Xiaofang Zhang ◽  
Zhanhua Chen ◽  
Yue Xiao ◽  
Yunhui Fang
Keyword(s):  
Molecular Weight ◽  
Adsorption Capacity ◽  
Cement Paste ◽  
Cement Hydration ◽  
Main Chain ◽  
Chain Structure ◽  
Hydration Process ◽  
Side Chain ◽  
Structure Parameters ◽  
Polycarboxylate Superplasticizer

Abstract Polycarboxylate superplasticizer is synthesised by different acid to ether ratio, which is changing the main chain structure parameters, obtained different microstructures. The effect of different microstructure PCE superplasticizer on the fluidity of cement paste, rheological thixotropy, adsorption capacity and hydration heat are studied. The results show that dispersing performance in cement with acid to ether ratio of 3.5 is the best, the molecular weight and side chain density have rather little effect on the cement hydration process.

Effects of Molecular Structure of Polycarboxylate Water Reducers on their Performance in Cement Paste

2010 ◽  
Vol 168-170 ◽  
pp. 1854-1858
Author(s):  
Shun Li ◽  
Qi Jun Yu ◽  
Jiang Xiong Wei ◽  
Ya Jun Ji
Keyword(s):  
Molecular Structure ◽  
Molecular Weight ◽  
Induction Period ◽  
Cement Paste ◽  
Cement Hydration ◽  
Side Chain ◽  
Medium Density ◽  
Dormant Period

The polycarboxylate water reducers(PCs) with different molecular structure were synthesized. The effects of molecular structure on their performance in cement paste were investigated. The results show that the PCs with a medium density of PEO side chain and/or a moderate molecular weight and its distribution have a higher dispersibility and a stronger dispersion retention stability at the same time, and that those PCs with a shorter PEO side chain exhibit a stronger dispersion retention stability. The PCs with a higher molecular weight, a lower density and/or a shorter length of PEO side chain are more easy to adsorb on the surface of cement particles. The earlier induction period is shortened while the dormant period is prolonged during the process of cement hydration in the presence of PCs. The PCs with a shorter PEO side chain show a stronger retarding effct. This effect is not very obvious with the decreasing molecular weight.

Optimum Study and Engineering Application of Mixing Ratio for C50 Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 537-540 ◽  
Author(s):  
Xiao Sheng Song ◽  
Guo Qiang Xu
Keyword(s):  
Concrete Strength ◽  
Engineering Application ◽  
Concrete Mixture ◽  
Orthogonal Experimental Design ◽  
Mixing Ratio ◽  
Polycarboxylic Acid ◽  
Mixture Ratio ◽  
Acid Type ◽  
Type Water ◽  
And Performance

The influence of fly ash content, water-cement ratio, sand ratio and polycarboxylic acid type water-reducer dosage on the early-strength and performance of C50 concrete is investigated combined with engineering application. The concrete mixture ratio is optimized by the orthogonal experimental design. Concrete strength, slump and slump loss are verified by experiments. Application results show the designed concrete mixture ratio reaches the expected requirements

Influence of Acid/Ether-Ratio on Composition and Dispersive Property of Polycarboxylic Type Water Reducers

2015 ◽  
Vol 1119 ◽  
pp. 245-250
Author(s):  
Chong Zhi Li ◽  
Fang Cai Zhang
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
Cement Paste ◽  
Average Molecular Weight ◽  
Polymerization Degree ◽  
Molar Ratios ◽  
Dispersive Property ◽  
Gel Permeation ◽  
Type Water ◽  
Fluidity Test

Polycarboxylic type water reducers were synthesized at different molar ratios of acrylic acid to methyl-allyl polyethylene glycol2400 (acid/ether-ratio). Influence of the acid/ether ratio on its composition and dispersive property were studied by means of Gel Permeation in Chromatography (GPC) and fluidity test of cement paste. The GPC analysis results showed that the average molecular weight and polydispersity were increased with the increase of acid/ether-ratio, but the polymerization degree should be no longer increased as which reached to a certain value, the excessive small-monomers would be self-polymerized when macro-monomers had been consumed. As the final product of polymer at an acid/ether ratio of 5:1, was composed of un-reacting macro monomer (about 6%) and the copolymer of water reducers (about 92%) and the copolymer of small monomers (about 2%). The result of fluidity of cement paste showed that the acid/ether-ratio also influenced the dispersive property to different cement, its ability would be bad if at the ratio of 2:1, then the property of dispersive and fluidity retaining should be all well if at 3.5:1, and the beginning dispersive ability might be high but the ability of fluidity retaining be low as the ratio was beyond 4.5:1.

Sign in / Sign up

Export Citation Format

Share Document