Synergistic effect of polycarboxylate superplasticizer and silica fume on early properties of early high strength grouting material for semi-flexible pavement

Abstract

Nowadays, the application of early high strength grouting material (EHSG) is in line with the development trend of semi-flexible pavement. In this paper, the synergistic effects of polycarboxylate superplasticizer (PCE) and silica fume (SF) on the properties of EHSG were studied. The results suggest that the flow time of slurry with high fluidity has a linear relationship with its dynamic yield stress. The mechanism of PCE and SF on rheological properties was analyzed via water film thickness (WFT), zeta potential, PCE adsorption, and SEM. It can be found that the crucial role of SF on slurry is to improve the adsorption of PCE on binders. The model describing the synergistic effect of SF and PCE on the particle aggregation of EHSG is proposed. SF addition weakens the interlocking effect and reduces the friction but may form the interparticle bridging effect between cement grains. PCE can not only inhibit the aggregation of cement grains but also mitigate the bridging effect of SF.