泵送大体积混凝土塑性裂缝分析及控制措施——以黑河大孤山水电站为例

Analysis of mass pumping reinforcing concrete plastic cracks and control measures——Taking Heihe Dagushan hydropower station project as an example

为了控制裂缝对水利工程中泵送大体积混凝土产生的不利影响,试验结合黑河大孤山水电站项目,对塑性裂缝进行了分析研究.试验设置了试验区一(闸室底板)和试验区二(消力池底板),分别采取一次振捣和二次振捣的施工工艺,比较分析了混凝土在凝结过程中产生的裂缝及裂缝长度的变化情况.结果显示,两个试验区混凝土裂缝均在初凝后8h内发展迅速;混凝土在初凝后24h,试验区二混凝土裂缝长度明显小于试验区一,两者最长裂缝差值可达102mm.根据研究结果,对水利工程泵送大体积混凝土塑性裂缝的判定进行了总结,并提出了防止混凝土塑性裂缝发展的控制措施.

In order to control the adverse effects of cracks on mass reinforcing pumping concrete, the plastic cracks on the basis of Heihe Dagushan hydropower station project were analyzed and researched. Two treatments with different construction technologies in the concrete construction were set. One was vibrated only once, the other was vibrated twice. The plastic cracks in the process of concrete condensation were analyzed and researched. According to the results, the concrete cracks grew quickly during the eight hours both in the two treatments. Cheek the No. 1 treatment against the No. 2 treatment, the concrete cracks in the latter which was vibrated twice grew slowly. Compared to the finally cracks, the difference reached was 102 mm. The method to judge the concrete plastic cracks was summarized and the measures to control the concrete cracks in the mass pumping concrete was proposed