高温后混凝土的裂缝张开位移

Crack Opening Displacement of Concrete Exposed to High Temperature

摘要:

进行了高温后混凝土楔入劈拉法断裂试验，研究裂缝扩展全过程中裂缝口张开位移与裂缝尖端张开位移之间的关系.根据裂缝口张开位移裂缝尖端张开位移曲线判断起裂荷载,并与采用荷载裂缝口张开位移判断的起裂荷载进行比较，两者能较好吻合.采用两参数和铰链模型由实测裂缝口张开位移值计算裂缝尖端张开位移，并与试验尖端张开位移值进行比较，发现两参数模型更为准确.确定高温后混凝土楔入劈拉试件裂缝尖端张开位移与裂缝扩展长度的关系，两者呈指数关系.

Abstract:

Wedge splitting test was carried out on the concrete exposed to high temperature to investigate the relationship between crack tip opening displacement ω and crack mouth opening displacement δ during the whole fracture process. It is found that the initial cracking load determined from δ ω curve shows a good coincidence with that determined from load crack mouth opening displacement (P δ) curve. The value of ω was calculated from δ based on the two parameters fracture model and hinge model, and the comparison with the experiment data show the two parameters fracture model has a better accuracy. Finally, the exponent relationship of ω and crack extension Δa was established.