The role and interaction of superplasticizer and emulsifier in fresh cement asphalt emulsion paste through rheology study

Abstract

The workability and mechanical properties of cement asphalt emulsion (CA) mortar are unstable due to the complex interaction between cement and asphalt emulsion. To reveal the interaction between cement and asphalt emulsion, the effect of emulsifier and superplasticizer on the rheology of cement paste and asphalt emulsion is investigated, respectively, and the effect of the interaction between emulsifier and superplasticizer on the rheology of cement paste is studied in this paper as well. Results show that the apparent viscosity and yield stress of asphalt emulsion increase with superplasticizer and emulsifier dosage. Emulsifier can change the yield stress and apparent viscosity of cement paste, and its effect on cement paste differs greatly with the type and dosage of emulsifier. Some emulsifiers can increase the yield stress of cement paste, but some emulsifiers can decrease the yield stress of cement paste. Emulsifier has interaction with superplasticizer, thus affecting the reducing water effect of superplasticizer on cement paste. There is a competition relationship between emulsifier and superplasticizer when they are adsorbed by cement particles. The mixing method, in which superplasticizer is mixed with cement before emulsifier added, is beneficial to obtain a lower apparent viscosity of cement paste for all tested emulsifiers.

Retardation mechanism of anionic asphalt emulsion on the hydration of Portland cement

“…Therefore, the anionic asphalt emulsion could only exert some slight hindrances to the hydration of C3S and C2S. As it is the hydration of C3S and C2S that mainly contributes to the strength development of PC paste, it could be deduced that anionic asphalt emulsion is more suitable than cationic asphalt emulsion for formulating CA mortars when a higher strength is required (such as the Type II CA Mortar as specified in the current Chinese Standard) [17][18][19]. However, the effect of anionic asphalt emulsion on the hydration of -3-PC has not been fully understood.…”

Influence of Emulsifier on Surface Mass Transfer Based on Molecular Dynamics Simulations

“…Experimental results indicate that the response of the electrical resistance of composites with SDBS to external force is more stable and sensitive than that of composites with Sodium dodecyl sulfate. Ouyang et al (2016) studied the effect of emulsifier and superplasticizer on the rheology of cement paste and asphalt emulsion and the results show that the apparent viscosity and yield stress of asphalt emulsion increase with superplasticizer and emulsifier dosage. Wang et al (2018) synthesized a new cationic surfactant containing non-ionic aliphatic alcohol polyoxyethylene ether using epichlorohydrin, octadecyl dimethylamine, and aliphatic alcohol polyoxyethylene ether as raw materials.…”

Rheological Behavior of Fresh Cement Pastes

“…Another aspect that must be considered when several chemical admixtures are simultaneously used in the formulation of the same cement paste is its synergic effect [62][63][64][65]. For example, it was observed that a polysaccharide viscosity-modifying agent (Welan Gum) has a higher influence on rheological properties of cement pastes formulated with an ester polycarboxylate superplasticizer than when it was formulated with an ether polycarboxylate [66].…”