Influence of Varying Curing Temperatures on the Mechanical and Durability-Related Performance of Multi-SCM Blended High-Strength Self-Compacting Concrete

Self-compacting concrete (SCC) offers major advantages in construction; however, its high paste content makes its performance highly sensitive to curing temperature and binder composition. This study evaluates the mechanical and durability behaviour of high-strength SCC incorporating silica fume (SF), metakaolin (MK), fly ash (FA), and a quaternary blend of these materials under different curing temperatures. The mixtures were cured at 10 °C, 20 °C, 35 °C, and 50 °C, and their compressive strength, sorptivity, bulk electrical resistivity, and length change were monitored up to 90 days. The results indicate that elevated curing temperatures significantly enhance early-age strength and reduce sorptivity and electrical conductivity, particularly in mixtures containing SF and MK, due to accelerated hydration and pore refinement. However, these conditions also led to increased length change, indicating greater deformation at both early and later ages. In contrast, curing at 10 °C reduced early strength but consistently improved long-term durability performance, especially in FA-containing mixtures, by promoting gradual hydration and reduced shrinkage. The quaternary blend exhibited balanced behaviour across all temperature regimes, achieving improved early strength while maintaining favourable long-term durability indicators. The innovation of this study lies in the integrated assessment of mechanical performance, transport properties, and dimensional stability of SCC incorporating multi-SCM systems under a wide range of curing temperatures, providing new insights into achieving stable and durable SCC performance under variable thermal conditions.