A practical approach for ultra high performance concrete construction

"Ultra-high-performance concrete (UHPC) with compressive strengths in excess of 150 MPa promise to enhance the structural efficiency and durability of concrete-based infrastructure systems. In order to transition UHPC materials into mainstream construction practices, there are needs to develop refined mix design procedures that enable production of UHPC using primarily locally available materials, resolves the problems with production of homogeneous UHPC mixtures using commonly available concrete mixers, develop convenient fresh mix workability test methods that consider the peculiar rheology of fresh UHPC mixtures, and quantify some aspects of the UHPC material properties that have not been fully characterized. The UHPC materials were tested for fresh mix flow and hardened concrete compressive strength. The trends in the effects of packing density, water film thickness and excess paste film thickness on compressive strength and fresh mix flow were investigated. The results were used to identify viable ranges of these defining characteristics of UHPC mixtures. Response surface analysis of the fresh mix flow and the hardened concrete compressive strength test results led to identification of the optimum values of mix design parameters. The optimum mix was prepared, and was found to produce a highly desired balance of fresh mix flow and hardened concrete compressive strength, which occurred within the ranges predicted by response surface analysis of experimental results."--Page ii.