A probabilistic approach to the design of reactive powder concrete mixes modified using slag

Abstract

Abstract Reactive Powder Concretes (RPC) are well known for their strength, durability, and sensitivity to the environment. RPCs are composed of very fine powders such as Ordinary Portland Cement (OPC), Silica Fume (SF), Quartz Powder (QP), etc. Aiming to develop sustainable RPC, in this study, the cement used is partially replaced with Ground Granulated Blast-furnace Slag (GGBS). The replacement was done at different levels, such as 0%, 10%, 20%, 30%, and 40% of cement by mass. Further, QP is replaced with Rice Husk Ash (RHA) at three different levels, such as 0%, 50%, 100%. 2% of crimped steel fibers by volume of concrete were used to reinforce the matrix. As there are no comprehensive design approaches for Reactive Powder Concretes (RPC), many trials are required to optimize the fresh and hardened properties of mixes. The workability for different mixes was evaluated in terms of flow percentage. Hardened properties such as compressive strength and split tensile strength after 28 days of standard water curing were evaluated. Also, this paper describes a factorial design approach to the optimization of flow and maximization of compressive strength and split tensile strength of RPC mixes. It was observed that the flow was increasing with an increasing amount of GGBFS in the mix and decreasing due to the addition of RHA. It was also observed that the strength results were progressively improving up to 20% replacement of cement with GGBS and was getting deteriorated for further replacement. The full replacement of QP with RHA also helped in the betterment of strength. The numerical models developed were competent to predict and optimize the results.