碾压混凝土层面双G断裂参数的试验研究

Experimental study on double G fracture toughness parameters of RCC layer surfaces

通过对不同形式的碾压混凝土层面及本体试件进行楔入劈拉试验,得到了各种层面形式的能量型断裂参数,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。通过对断裂参数规律的分析得出,本体试件的失稳断裂韧度最大,终凝后处理的层面形式的试件次之,初凝与终凝之间处理的层面形式的试件更小,初凝前处理的层面形式的试件最小。层面间隔时间相同的情况下,层面经过处理的试件要比层面不处理的试件的失稳韧度大;层面处理方式相同的情况下,层面间隔时间短的试件的断裂韧度比间隔时间长的略大。

The energy mode fracture parameters both the initial fracture toughness and unstable fracture toughness of RCC specimens with different layer surface conditions and specimens of dam body were experimentally studied by wedge splitting test. The effects of layer surface treatment and time interval for placement of layers on fracture properties are investigated. The result indicates that the unstable fracture toughness of dam body specimen is the highest, the specimen with layer surface treated after the final setting is the next highest, the specimen with layer surface treated in the period between initial setting and final setting is lower and the worst one is the specimen with the layer surface treated before initial setting. Under the condition of the same time interval the fracture toughness of the specimens with treated layer surfaces is higher than that of untreated. The toughness of specimen with shorter placing time interval is a little bit higher than that of longer time interval.