碾压混凝土层面断裂及劈拉破坏试验研究

Experimental Research of Fracture and Splitting Failure of RCC Layer Surfaces

通过用不同工况的碾压混凝土试件近似模拟碾压混凝土初凝前层面、中间型层面和终凝后层面及本体形式并进行I型断裂试验。通过对试验结果进行分析,总结了各种层面形式的断裂韧度的规律,比较了层面处理方式和间隔时间对于层面断裂性能的影响。同时进行了层面劈拉试验,并比较了层面I型断裂特性与抗拉强度特性之间的规律。得到了本体试件的失稳韧度最大,终凝后层面形式的次之,中间型层面形式的更小一些,初凝前层面形式的最小及层面相对于本体的断裂破坏比强度破坏更为脆弱的结论。

Many engineering situations were adopted to simulate layer surface before initial setting time, middle layer surface, layer surface after final setting time and body formations and mode I fracture experiment were performed. The variation of fracture toughness of all kinds of layer surface was summarized on the analysis of tests results. The effect of treatment and interval time of the RCC layer surface on fracture properties of that were compared. At the same time, splitting tensile experiment of layer surfaces was performed, and variation of characteristics of mode I fracture and tensile strength was compared. Some conclusions were drawn that unstable fracture toughness of body specimen was the largest, which of layer surface after final setting time was a little smaller than that of body specimen, which of layer surface before initial setting time smaller than that of layer surface after final setting time, which of middle layer surface was the smallest and fracture failure of layer surfaces to body was weaker than strength failure of layer surfaces to body.