纤维在堆石坝面板水工混凝土中的应用分析

Analysis on Application of Fiber in Hydraulic Concrete of Rockfill Dam Panel

受钢筋及基础的约束作用,堆石坝面板层混凝土极易产生早期干缩裂缝及塑性裂缝,试验研究聚丙烯纤维和纤维素纤维对面板混凝土抗冻性、抗渗性的影响及其早期干缩裂缝、塑性裂缝的作用。试验表明:在混凝土塑性阶段聚丙烯与纤维素纤维的减裂率达到50.4%、87.3%,减裂效果显著;对早期干燥收缩裂缝聚丙烯与纤维素纤维的减裂率达到51.9%、66.2%,具有明显的裂缝抑制效果;对改善混凝土抗冻性及抗渗性,聚丙烯纤维与纤维素纤维可提高1个、2个抗渗等级,提高50个抗冻性标号。

Early dry shrinkage crack and plastic crack are easily produced in the concrete in the face layer of rockfill dam due to the restraint of reinforcement and foundation.The effects of polypropylene fiber and cellulose fiber on the frost resistance and impermeability of concrete in face layer and the effects of early dry shrinkage crack and plastic crack are studied.The results show that the crack reduction rate of polypropylene and cellulose fiber reaches 50.4% and 87.3% in the plastic stage of concrete,and the crack reduction effect is remarkable.The cracking reduction rate of polypropylene and cellulose fibers with early drying shrinkage cracks reached 51.9% and 66.2%,which had obvious cracking inhibition effect.To improve the frost resistance and impermeability of concrete,polypropylene fiber and cellulose fiber can increase 1 and 2 impermeability grades,and increase 50 frost resistance marks.