Effect of thermal cycling on the mechanics and microstructure of ultra-high performance concrete

• DOI: 10.1016/j.conbuildmat.2024.135878
• Publication Date: 2024-03-27T10:42:35Z
• Authors: Hongqiang Ma; Shaochen Zhang; Hao Fu; Shiru Li; Maozheng Su; Chao Wu
• Keywords: Temperature cycling; Cycling

This study investigates the mechanical and microstructural responses of Ultra-High Performance Concrete (UHPC) subjected to a substantial number thermal cycles upto 300 times from ambient temperature 60°C. The experimental findings reveal distinctive pattern behavior in static compressive strength, characterized by an initial increase, followed subsequent decline, modest resurgence as cycling progressed. Notably, peak flexural strengths were attained after 120 cycles, whereas maximum dynamic strength was observed 60 cycles. It is worth highlighting that increase factor (DIF) exhibited inverse trajectory comparison strength. After stress-strain curves under impact loads pronounced strain softening characteristics, with oscillation state duration 250μs, which surpassed ascending descending phases. variances macroscopic properties can be attributed several pivotal factors, including quantity hydration product, mean chain length (MCL) calcium-silicate-hydrate (C-S-H) gel, distribution pore volume, presence micro-cracks. comprehensive examination serves valuable theoretical empirical foundation for advancing utilization UHPC applications prolonged intricate conditions.