Toward the prediction of rheological properties of self-consolidating concrete as diphasic material

Abstract

Understanding the rheology of self-consolidating concrete (SCC) is a key step to ensuring proper flow and successful casting in formworks, and hence good performance of the hardened material. The rheology of SCC is a function of several mixture parameters, including water-to-binder ratio (W/B), paste content, coarse aggregate content and grading, and presence of chemical admixtures. The mix design of SCC is less robust than conventional concrete and necessitates vigorous optimization to ensure adequate flow performance. The research emphasis in this study is on developing a practical approach that can be used to predict rheological properties of SCC as a diphasic material, which will contribute significantly to simplifying the protocols for mixture optimization and material selection. Various SCCs and their corresponding mortar mixtures were investigated covering a wide range of mixture proportion parameters, including W/B, paste-to-sand volume (VP/VS), and coarse aggregate (CA) type and content. The rheological properties of SCC, mortar phases, and the relationship between the two phases are evaluated and discussed in this paper. Test results show very good correlation between the rheological properties of modified design mortar, sieved mortar, and SCC mixtures. Prediction adequacy was mostly affected by VP/VS and W/B parameters. Modified Krieger–Dougherty (KD) and Chateau–Ovarlez–Trung (COT) models satisfactorily predicted the rheological properties of SCC mixtures.