A critical review on high temperature performance of sustainable cementitious materials

Sustainable concrete materials have gained significant attention due to their potential to reduce CO2 emissions in the construction industry. However, these materials often exhibit distinct physical and chemical properties compared to traditional concrete, potentially affecting their performance at elevated temperatures. This review critically examines the high-temperature behavior of promising sustainable concrete materials, including supplementary cementitious materials (SCMs) blended OPC systems, ultra-high-performance concrete (UHPC), recycled aggregate concrete (RAC), alkali-activated concrete (AAC), limestone calcined clay cement (LC3), and CO2-cured concrete, by analyzing their spalling behavior, mechanical properties, and microstructural changes. SCM-blended systems show varying performance based on material type, with fly ash generally enhancing thermal stability, slag improving strength retention, and silica fume potentially increasing spalling susceptibility. UHPC demonstrates superior mechanical properties but increased spalling risk, which can be mitigated through fiber addition. RAC performance varies depending on recycled aggregate characteristics, with some studies reporting comparable or enhanced high-temperature behavior relative to traditional concrete. AAC generally exhibits good fire resistance, influenced by precursor materials and activator type. LC3 concrete shows similar strength retention to ordinary Portland cement concrete at moderate temperatures. CO2-cured concrete performs well up to 600 °C but experiences rapid degradation at higher temperatures due to calcium carbonate decomposition. This review elucidates the mechanisms influencing sustainable concrete performance at elevated temperatures and identifies critical research directions to enhance their fire resistance for broader adoption in construction applications.