Proportioning and characterization of reactive powder concrete for an energy storage pile application

Reactive Powder Concrete (RPC) is a newly emerging concrete material that is being used for various applications where high-strength concrete is required. RPC is obtained by removing coarse aggregates and adding fine powders such as silica fume into the concrete mixture. This research has focused on the proportioning and characterization of RPC mixture to be used as a material for energy storage pile application. For mixture parameters, the water-to-binder ratio (WB), silica fume (SF) content, and normal and warm temperature curing have been selected. The relative flowability, penetration resistance, setting time, drying shrinkage, and compressive and flexural strengths were evaluated. Based on the test results, the mixture with WB = 0.22 and SF = 20% was the best mixture with the highest tensile strength and other characteristics. Response surface methodology (RSM) was used to design the experiments and find the optimum mixture proportions to achieve the highest compressive strength. The optimum WB and SF content to achieve the highest strength for combined ages (7 days, 28 days, and 56 days) was determined to be WB = 0.213 and SF = 20%. Through the comparison between the test results and the required strength from analytical simulations, the RPC studied in this paper was deemed to be suitable for the energy storage pile.