Proportioning and Characterization of Reactive Powder Concrete for an Energy Storage Pile Application

Abstract

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.

Group Pile Effect on Temperature Distributions inside Energy Storage Pile Foundations

“…The integration time increment was automatically adjusted during the simulation to control the Courant-Friedrichs-Lewy value to be no more than 1.0. The concrete cracking effect on the thermal properties was ignored because the proposed new energy storage foundation uses high-performance concrete limiting the development of cracks [5,29]. The cyclic thermal loading follows the temperature change curve of a one-day cycle, as shown in Figure 4b.…”

Temperature Distributions inside Concrete Sections of Renewable Energy Storage Pile Foundations

“…The compressed air can result in high air pressure at the inner surface of the pile foundation. Extensive analytical and experimental studies have been conducted for the pile foundation subjected to the high air pressure for different pile construction materials, including regular reinforced concrete [7], fiber reinforced concrete [8], high-performance concrete [9,10], steel [11], and steel-concrete composites [12]. In these studies, the compressed air is assumed to go through a complete cooling process, where the temperature of the compressed air will drop back to normal room temperature [7].…”

“…The Courant-Friedrichs-Lewy is controlled to be less than 1.0 by automatically adjusting time integration incrementation during the simulation. Nonlinear thermal properties and the concrete cracking effect were not considered in the simulation due to the fact that the proposed new energy storage foundation requires limited cracks or even crack-free by using fiber reinforced concrete and high strength [8,9]. The temperature change follows the 24 h cycle, as defined in Figure 3a.…”

Effect of Aggregate Packing on Strength of Reactive Powder Concrete: Modeling and Experimental Evaluation

“…Hence, the elimination of coarse aggregates in RPC results in the reduced porosity and higher mechanical strength due to the absence of ITZ related microstructural flaws [3]. Superior mechanical and durability properties of RPC are achieved by appropriate mixture design and curing conditions [4,5]. To achieve reduced porosity and improved microstructure, linear packing density model (LPDM) is used for the mixture design of concrete [6].…”