RPC MIX OPTIMIZATION BY DETERMINATION OF THE MINIMUM WATER REQUIREMENT OF BINARY AND POLYDISPERSE MIXTURES

摘要

Reactive powder concrete (RPC) is an ultra high performance material which development was strongly associated with the maximization of the packing density. This paper presents an alternative approach for the optimization of the mix design of RPC by using the determination of the water demand of binary, ternary and polydisperse mixes. Measurements of the water demand of quartz/sand and quartz/sand/cement/silica fume mixes were performed. The control mixes-having water to binder ratio of 0. 187, 25% of silica fume and 5% of superplasticizer measured from cement content-were produced for the assessment of fresh concrete properties and compressive strength. The concretes were heat-treated at 90°C. The results showed that maximum compressive strength was obtained in concretes having binary quartz/sand mixes characterized by the highest packing density. The best rheorogical properties were obtained in mixes, which had the highest packing density when measured on polydisperse mixes containing all RPC components.