大体积混凝土水化热温度变化光纤监测技术研究

摘要

This paper uses the Raman Optical Time Domain Reflectometer(ROTDR)and Fiber Bragg Gratting (FBG)to monitor the hydration heat of large base-slab concreting for ship lock.The base-slab is 14.8m wide, 29.2m long and 3m thick.The monitoring shows the following results.The peak temperature in core of the concrete block thick can reach 54.5℃at the 5th day after the concreting.The surface temperature can reach the peak temperature 46.7℃at the 6th day.According to the monitoring results,a comprehensive analysis of concrete hydration heat release process is carried out to verify the feasibility of ROTDR and FBG to be used in monitoring the hydration temperature field changes during mass concreting.These results can provide reliable data for appraisal of safety and stability of the ship lock.%本文采用拉曼散射光时域反射（ROTDR）光纤测温技术监测船闸工程闸首底板大体积混凝土浇筑水化热释放过程中混凝土结构内部的温度变化，采用布拉格光栅（FBG）光栅测温技术监测混凝土表层的温度变化。监测结果表明，结构尺寸为14.8m×29.2m×3m的底板在混凝土浇筑完成第5d时内部温度后达到最大值，最大值为54.5℃，底板混凝土上、下表层的温度达到最大值时间相对较晚；在混凝土浇筑完成第6d时上表层温度达到最大值46.7℃；在混凝土浇筑完成第10d时下表层温度达到最大值46.5℃。根据监测结果，综合分析了混凝土水化热释放过程，并验证了ROTDR和FBG技术应用于大体积混凝土浇筑水化热温度场变化过程监测的可行性。研究成果对于完善分布式光纤温度感测技术，优化船闸工程结构的设计、施工和维护具有重要意义。