Effects of fineness and substitution ratio of limestone powder on yield stress of cement suspensions

This paper aims at investigating the evolution of the yield stress of cement suspensions with the variation of its properties for an environmentally friendly alternative material of cement clinker, the limestone powder (LP). We first showed that the yield stress of cement suspensions varies significantly with different particle size distribution, LP substitution ratio and superplasticizer dosage. We then showed that for the cement suspensions without superplasticizer, the yield stress is dominated by the impacts of the median particle size and maximum packing fraction of the binary powder mixtures. However, for the cement suspensions with low dosage of superplasticizer, the yield stress of the LP substituted suspensions decreases with the increase of the substitution ratio. It is finally suggested that the impact of superplasticizer on the yield stress is conspicuous in the condition of similar median particle size and packing properties while can be neglected in the case of the significant change of the particle size of the powder mixtures.