Abrasion and impact resistance of concrete under different curing conditions

This study aims to assess the mechanical properties, impact resistance, and abrasion resistance of a series of self-consolidating concrete (SCC) and normal vibrated concrete (NVC) mixtures under different curing conditions. The studied variables included coarse-to-fine (C/F) aggregate ratio (0.7 and 1.2), water-to-cement (w/c) ratio (0.4 and 0.55), the addition of 0.35% steel fibers (SFs), and the use of different supplementary cementing materials (SCMs) types (metakaolin (MK) and silica fume (SLF)). The research program was divided into three stages. The first stage included trial mixtures to optimize a number of SCC mixtures with different proportions. In this stage, the appropriate percentages of SCMs (MK or SLF) and the maximum percentage of SFs that can be used to develop successful SCC were optimized. The second stage included evaluation of the compressive strength, splitting tensile strength, and impact resistance of the optimized mixtures. The third stage investigated the flexural strength, modulus of elasticity, and abrasion resistance of the same optimized mixtures. All studied samples were cured under four different curing conditions, including moisture curing conditions at 23º C, air curing at 23º C, and cold temperatures curing conditions at +5º C and -10º C. Curing concrete at +5º C showed significant reductions in the abrasion strength, compressive strength, splitting tensile strength (STS), and impact resistance, when compared to moisture curing at 23º C. The magnitude of these reductions significantly increased when curing concrete at -10º C. Mixtures with higher C/F ratio, or higher w/b ratio, or mixtures with SFs or SCMs were more affected by the cold curing compared to the control mixture. The results also showed that cold temperature curing had a more pronounced negative effect on the impact resistance and STS compared to the compressive strength