Effect of side chains on the dispersing properties of polycarboxylate-type superplasticisers in cement systems

Peng, Xiongyi; Li, Xia; Chen, Dongzhi; Ma, Dawei

doi:10.1680/macr.12.00111

Cited by 10 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Superplasticiser contacts with cement particles and adsorbs onto the surface of cement particles to disperse particles (Flatt et al, 2009;Peng et al, 2013;Winnefeld et al, 2007;Yoshioka et al, 2002;Yu et al, 2013). Adsorption behaviour is the first step in the interaction between SP and cement particles.…”

Section: Introductionmentioning

confidence: 99%

Effect of superplasticiser and sodium tripolyphosphate on fluidity of cement paste

Tan

Huang

et al. 2014

Magazine of Concrete Research

View full text Add to dashboard Cite

The effect of sodium tripolyphosphate (STPP) on the fluidity of cement paste with lignin sulfonate (LS), sulfonated naphthalene formaldehyde condensate (FDN) and polycarboxylate ether (PCE) superplasticiser (SP) was studied. The adsorption amounts of LS, FDN and PCE were assessed using UV spectrophotometry and total organic carbon analysis; the concentration of Ca 2+ ions in solution and the adsorption amounts of STPP were tested with plasma emission spectrometry and the electrokinetic properties of the cement particles were confirmed using ae-potential measurements. Based on analysis of the adsorption amounts, the Ca 2+ concentration, ae-potential and fluidity of cement paste, the competitive adsorption between SPs and STPP was investigated. The result shows that SP and STPP can all adsorb onto the surface of cement particles and there is competitive adsorption between STPP and SP. STPP prevents Ca 2+ releasing and pre-empts the adsorption sites of SP; it causes a reduction in the adsorption amount of SP and increases the ae-potential of cement particles. The SP also reduces the adsorption amount of STPP. Competitive adsorption causes changes in fluidity and fluidity loss. STPP can improve the initial fluidity and reduce fluidity loss of cement paste with LS or FDN. With PCE and STPP, the initial fluidity can be improved, but fluidity loss increases; this is due to the different molecular structure of the SPs. It is thus suggested that STPP can be used with LS and FDN to improve fluidity and reduce fluidity loss, but it is a disadvantage when used with PCE.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of superplasticiser and sodium tripolyphosphate on fluidity of cement paste

Tan

Huang

et al. 2014

Magazine of Concrete Research

View full text Add to dashboard Cite

show abstract

“…However, the admixture with short side chains may exhibit a negative dispersion capability in the mixture, although it has the highest absolute value of the negative Zeta potential. This may be due to being the inefficiency of the steric effect of the short side chains of the admixture 15 . In addition, the longer the admixture main chain is, the greater the number of anionic functional groups on the main chain is.…”

Section: Resultsmentioning

confidence: 99%

“…As it is known, in the event that there is excessive of admixture in the system, the admixture remains free in the solution since the admixture adsorption reaches a saturation point. In this way, the chemical admixture released in the solution blocks the admixtures adsorbed onto the cement surface, causing a reduction in the steric effect 15 …”

Section: Resultsmentioning

confidence: 99%

Effect of main and side chain length change of polycarboxylate‐ether‐based water‐reducing admixtures on the fresh state and mechanical properties of cementitious systems

Özen

Altun

Mardani‐Aghabaglou

et al. 2020

Structural Concrete

View full text Add to dashboard Cite

In this study, the effect of both main and side chain length changes of the admixtures on some properties of cementitious systems were investigated. Three different polycarboxylate‐ether‐based water‐reducing admixtures (WRA) having constant molecular weights and different main and side chain lengths were synthesized. Single type of raw material and carboxylate functional group were used in all WRAs. The molecular weights, free nonionic contents, and anionic/nonionic ratios of the admixtures were kept constant. Test results showed that degree of fluidity was observed in cement paste and mortar mixtures in case the admixture main and side chain length is more or less than a critical value. This negative effect is thought to be due to the weakening of the adsorption ability by the chain length change of the admixtures, the being tendency of polymers to intertwine and the adsorbing of admixture on several cement particles simultaneous. Admixtures having excessive long or short main chain and side chain improved the time‐dependent slump‐flow retention of the mortar mixtures. The admixtures with short main and side chains had insufficient adsorption ability and the admixture with excessive long main and side chains had the interlacing risk of polymers. In both cases, time‐dependent behavior improved because the amount of free admixture in solution increased. The change in the chain lengths of the WRAs affected the 1‐day compressive strength of the mortar mixtures.

show abstract

“…According to Sakata et al [35], when mixed well with a HRWR, welan gum would act as a liquified viscosity agent, which is caused by the swelling up of the welan gum particles, creating a stable suspension even without much of a viscosity increase. However, in the presence of cement particles, the naphthalene formaldehyde polycondensate would adsorb on to their surface [83,84], and with an increased adsorption, an increase in fluidity and reduction in fluid loss would be observed [85,86]. Thus, the amount of water necessary for the complete hydration of SREMA would be reduced.…”

Section: Effect Of Snsfmentioning

confidence: 99%

The Hydration and Volume Expansion Mechanisms of Modified Expansive Cements for Sustainable In-Situ Rock Fragmentation: A Review

Liyanage

Ranjith

2021

Energies

View full text Add to dashboard Cite

This review provides the hydration and volume expansion mechanism of expansive materials, with the goal of utilizing them in the development of sustainable mining methods. The main focus of the review will be the newly developed non-destructible rock fragmentation method, slow releasing energy material agent (SREMA), which is a modified soundless chemical demolition agent (SCDA). The review aims to address one of the main gaps in studies related to SREMA, by presenting a thorough understanding of the components of SREMA and their mechanisms of action, leading to volume expansion. Thus, this review would act as a guide for researchers working on using expansive materials for rock breaking. As many literatures have not been published regarding the recently discovered SREMA, studies on cements, expansive cements, and soundless chemical demolition agents (SCDA) were mainly considered. The chemical reactions and volume expansive processes of these materials have been studied and incorporated with the additives included in SREMA, to understand its behavior. Literature containing experimental studies analyzing the heat of hydration and microstructural changes have been mostly considered along with some of the heavily discussed hypotheses regarding the hydration of certain components, to predict the volume expansive mechanism of SREMA. Studies related to SREMA and other similar materials have shown drastic changes in the heats of hydration as the composition varies. Thus, SREMA has the capability of giving a wider range of expansive energies in diverse environmental conditions

show abstract

Effect of side chains on the dispersing properties of polycarboxylate-type superplasticisers in cement systems

Cited by 10 publications

References 24 publications

Effect of superplasticiser and sodium tripolyphosphate on fluidity of cement paste

Effect of superplasticiser and sodium tripolyphosphate on fluidity of cement paste

Effect of main and side chain length change of polycarboxylate‐ether‐based water‐reducing admixtures on the fresh state and mechanical properties of cementitious systems

The Hydration and Volume Expansion Mechanisms of Modified Expansive Cements for Sustainable In-Situ Rock Fragmentation: A Review

Contact Info

Product

Resources

About