The influence of pre-compression on the durability of high-performance concrete incorporating industrial by-products

Abstract

Critical compression impacts may significantly degrade the quality of high-performance concrete (HPC) over time, resulting in significantly reduced service life due to chloride and other corrosive chemical contamination. Moreover, the ability of HPC to resist water and chloride intrusion may degrade rapidly due to pre-compressive-induced damage caused by accelerated porosity development. Although chloride diffusivity in saturated concrete under compressive loading has been adequately discussed in the literature, few studies have addressed the impact of pre-compressive conditions on chloride ingress in HPC incorporating industrial by-product materials. Therefore, this study was designed to evaluate the influence of pre-compression on the porosity and durability of HPC incorporating industrial by-products. Three types of HPC were produced and used in this study, including conventional HPC (the control), HPC in which 35% of the ordinary Portland cement (OPC) was replaced by ground granulated blast-furnace slag (GGBFS; HPC1), and HPC in which 55% of the OPC was replaced by GGBFS (35%) and fly ash (20%; HPC2). These specimen mixtures were designed using an equivalent water-to-binder ratio of 0.30 and cured for up to 28 days. They were subsequently subjected to pre-compression at 0%, 55%, 70%, and 85% of the final compressive strength ( R28) and, afterward, subjected to a series of laboratory experiments to determine porosity, ultrasonic pulse velocity, chloride ion penetration, and water absorption at 28 and 56 days of curing. The proposed research is innovative in its use of material porosity and chloride infiltration factors to determine the impact of pre-loading intensity on HPC structures incorporating industrial by-products. In general, the results revealed that porosity in all of the specimens increased proportionally to the magnitude of the compressive load, while durability decreased proportionally to the pre-compression intensity. Notably, the pre-compression performances of the HPCs incorporating industrial by-products (HPC1 and HPC2) were much better than the control.