混凝土温控“内降外保”综合措施在放水河渡槽施工中的应用

Technology for temperature control of concrete applied in Fangshuihe Aqueduct construction

温度裂缝是混凝土施工中常见的一种裂缝类型,也是土木工程界至今难以很好解决的工程实际问题之一。在南水北调中线京石段工程放水河渡槽施工中,经过参建工程各方的努力,采取了预防和控制温度裂缝的一系列综合措施,槽身混凝土取得了在施工期未出现一条温度裂缝的良好效果,为野外高标号、大体积混凝土大规模施工提供了比较成功的范例。实践证明,在大体积、高标号混凝土的施工及在外部环境温度变化较大地区混凝土的施工中,可以采取综合温控措施预防和控制混凝土温度裂缝产生,或使结构尽可能不出现温度裂缝,尽量减少裂缝数量和宽度。

Temperature crack is one of the crack types often seen in concrete construction and also a practical problem existed in civil engineering construction that has not been solved. In the construction of Fangshuihe Aqueduct in Jing-Shi Section of Middle Route Scheme of South-North Water Diversion Project, a series of measures for controlling temperature crack was applied so that no crack was appeared during the construction period. It becomes a typical case for high strength and large-volume concrete application in field construction. It demonstrates that comprehensive temperature control measures can effectively prevent concrete crack or reduce the number and width of crack.