大孔径曲线形预应力管道灌注缓凝浆密实度改进方法研究

Improvement Method for Compactness of Retarding Slurry for Large Diameter Curved Prestressed Pipeline

预应力水平钢束管道起伏较多,管道灌浆过程中易在波峰下降等位置积存气体及泌水,形成空腔,影响灌浆密实度。以广西防城港核电工程预应力管道灌浆作为工程背景,分析影响灌浆密实度的主要原因。在灌浆速度选择、灌浆工艺设计、缓凝浆灌浆材料等方面研究改进措施,通过小比例试验进行验证。由试验结果可知,适当缩短缓凝浆初凝时间可减少泌水现象的产生;使用真空灌浆技术并选择合适的灌浆速度可提高灌浆密实度。

The prestressed horizontal steel tendon pipeline fluctuates a lot,during the pipeline grouting process,it is easy to accumulate gas and bleeding at the position where the wave crest drops,forming a cavity and affecting the grouting compactness.Taking the prestressed pipeline grouting of Guangxi Fangcheng Port nuclear power plant as the engineering background,the main reasons affecting the grouting compactness are analyzed.The improvement measures in the selection of grouting speed,grouting process design,retarding grout grouting materials are researched,and the small-scale test is carried out to verify the measures.It is concluded that properly shortening the initial setting time of retarding slurry can reduce the occurrence of bleeding,and then using vacuum grouting technology and selecting the appropriate grouting speed can improve the grouting compactness.