Hydration Heat Kinetics and Temperature Control in Ultra-Large Volume Concrete: A Case Study

Uneven temperature rise in large concrete structures, caused by cement hydration heat, can lead to thermal stress concentration, resulting in early cracking.This, in turn, affects the structure's functionality, durability, and overall integrity.To address this issue, this study focuses on the Jinan Yellow River Fenghuang Bridge in China, analyzing the hydration heat kinetics of ultra-large volume concrete and exploring temperature control measures.It also investigates the distribution patterns of temperature and stress in the joint section and foundation slab across different seasons.The findings reveal that in colder seasons, the temperature stress in the first layer of the joint section fluctuates significantly with age, strongly influenced by hydration heat.In contrast, during warmer seasons, the early-stage stress in the foundation slab is relatively low, but it increases rapidly in later stages.Therefore, temperature control measures need to be optimized to mitigate stress risks.Experimental and numerical simulation results show strong consistency, with errors not exceeding 5%, confirming the accuracy and reliability of the model.Based on these insights, the study proposes strategies for real-time monitoring, automatic early warnings, and precise temperature control through an intelligent system.In warmer seasons, enhanced cooling measures are recommended, while in colder seasons, increased insulation is necessary.These adjustments significantly reduce temperature-induced stress risks.The research offers both theoretical foundations and practical guidance for temperature control during the construction of ultra-large volume concrete structures, thereby improving engineering quality and ensuring structural safety.