首座跨海高铁斜拉桥承台温控设计研究

Study on temperature control design of abutment of the first cross-sea high-speed railway cable-stayed bridge

为防止处于高盐湿热海洋环境下的大体积混凝土浇注开裂,以首座跨海高铁斜拉桥为研究对象,通过设计优化混凝土配合比,建立了计算模型研究了大体积混凝土温控发展规律。结果表明:当P.O42.5水泥含量由310 kg降至280 kg及粉煤灰由125 kg增至142 kg后,混凝土抗压强度略有降低,且水化热绝热温升下降了5℃;基于有限元模型并结合绝热温升和热源函数计算公式,计算所得到混凝土内部最高温度值和温差值,与实测结果相比,偏差在2℃以内。

In order to prevent the pouring cracking of mass concrete in the hot and humid marine environment with high salt,taking the first cross-sea high-speed railway cable-stayed bridge as the research object,the mix design of concrete is tested,and a calculation model is established to study the development law of temperature control of mass concrete。The results show that when the content of P.O42.5 cement decreases from 310 kg to 280 kg and fly ash from 125 kg to 142 kg,the compressive strength decreases slightly,and the adiabatic temperature rise of hydration decreases by 5℃。Based on the finite element model,combined with the adiabatic temperature rise and heat source function calculation formula,the calculated maximum internal temperature and temperature difference are within 2℃compared with the measured results.