The Effect of Temperature and Ageing on the Behaviour of Self-compacting Concrete Containing Supplementary Cementitious Materials

Abstract

Self-compacting concrete (SCC) is increasingly replacing conventional vibrated concrete due to its high flowability and low energy demand during construction. The substantial proportion of paste found in SCC yields a different microstructure to conventional concrete, and thus, when subjected to different curing temperatures, it exhibits distinctive mechanical behaviour. However, the effect of curing temperature on SCC containing supplementary cementitious materials (SCMs) as partial cement replacements is yet to be thoroughly investigated. This paper aims to assess the behaviour of SCC with various SCMs cured at different temperatures to estimate the robustness and applicability of these mixes in concrete structures. For this study, certain percentage volume fractions of the cement in the SCC mixes were replaced by silica fume (SF), fly ash (FA), or ground granulated blast-furnace slag (GGBS). Tests were conducted on the fresh concrete to verify that the prepared mixes complied with the criteria for self-compacting concrete. Thereafter, cubes were made from the SCC mixes and cured at different temperatures (10, 20, 35, and 50 ℃). Cubic compressive strength tests were conducted at 1, 3, 7, 14, 28, 56 and 90 days. The results demonstrated that the strength gain tends to be slower at low curing temperatures (<20 ℃). In contrast, high curing temperatures (>20 ℃) could accelerate the strength gain in concrete but could also cause retardation of the strength development at a later age. However, using SCMs can make SCC more resistant to the detrimental effects of high curing temperatures.