光弹贴片法在混凝土裂缝扩展过程研究中的应用

Application of Photoelastic Coating Method in Studying the Process of Crack Developing in Concrete

采用光弹性贴片法对平面尺寸为3.6×3.0,3.0×2.5,2.4×2.0,1.8×1.5,1.2×1.0,0.6×0.5m^2的巨型紧凑拉伸试件预制裂缝的起裂,稳定扩展至失稳破坏的全过程进行了系统的研究,实验结果表明,在试件高达1米以上的实验范围内,失稳破坏前裂缝稳定扩展长度几乎是一个稳定的常数值,且与试件初始缝长a_0无关。还发现,宏观裂缝的起裂早晚与初始缝长a_0有关。

A systematic study for cracking, steady developing of crack and unstable failure of primary crack of huge compact tension specimen by means of photoelastic coating method are given in this paper. The plane size of specimens are 3.6×3.0, 3.0×2.5, 2.4×2.0, 1.8×1.5, 1.2×1.0, 0.6×0.5m^2. It is shown that the steady developing crack length is almost a steady constant and it is not related to the primary crack length α_0 before failure if the height of the specimen is more than one meter. It is also shown that the time of starting macroscopic crack is related to primary crack length α_0.