混凝土断裂能的边界效应  

Boundary effect of specimen on fracture energy in concrete

作　　者：赵艳华[1] 徐世烺[1] 聂玉强 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024 [2]中国土木工程集团公司,北京100038

出　　处：《水利学报》2005年第11期1320-1325,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点项目(50438010);国家973项目(2002CB412709)

摘　　要：本文从试件边界条件对断裂性能的影响出发,通过局部断裂能在韧带分布的连续光滑曲线假定,给出了真实的混凝土断裂能表达式,称为光滑曲线模型,并与受扰韧带模型及双线性模型进行了初步比较,同时,进行了4组不同韧带长度的楔入劈拉试验。结果表明,根据断裂功方法测得的混凝土断裂能的尺寸效应是由于局部断裂能在试件韧带上分布的不均匀引起的,而此分布特性受试件边界条件的影响;当试件尺寸足够大时由试验测得的断裂能即为混凝土的真实断裂能,也就是试验测试值的极限值;本文模型计算得到的混凝土断裂能与受扰韧带模型及双线性模型的计算结果非常接近,但3个模型在描述边界条件对其影响的程度上却各不相同,有待于做进一步研究。On the assumption that the distribution of local fracture energy along the ligament is continuous and smooth, the expression of concrete fracture energy, namely the smooth curve model, is proposed. The model is compared with two currently used models. At the same time wedge splitting tests for four sets of concrete specimen with different ligament length are carried out to study the fracture properties of concrete based on these three methods. The results show that the non-uniform distribution of local fracture energy reflecting the boundary effect along the ligament length is responsible for the size effect in the fracture energy obtained from the work-of-fracture method. Based on the test data of laboratory-scale specimens the true fracture energy can be obtained, which is actually the energy consumption in finite specimen. The results also reveal that the fracture energy obtained from different method are almost the same.

关 键 词：混凝土 断裂能 边界效应 尺寸效应 楔入劈拉试验 局部断裂能 

分 类 号：TU528[建筑科学—建筑技术科学]