混凝土裂缝成因研究进展

Research Progress in the Cause Analysis of Concrete Fracture

混凝土早期开裂主要取决于两方面因素:一方面是材料的固有的如收缩、弹性模量、抗拉强度和徐变松弛等性质的影响,这些性质都与混凝土硬化过程紧密相关,是伴随着龄期的发展而变化;另一方面是外部因素,如结构构件的构造、所受约束,以及环境温度湿度条件等。着重分析了在实际操作阶段混凝土早期约束条件下的应力应变及温度发展等规律。本文探讨评价了混凝土的收缩开裂、变形裂缝等,评述表明:根本上解决混凝土的裂缝是非常困难的。目前控制和防治最好的技术手段是用表征手法检查、检测,通过增大抗拉强度、扩大极限拉伸值、降低弹性模数。

The early cracking of concrete mainly depends on two factors： on the one hand,the inherent effects of the material such as shrinkage,modulus of elasticity,tensile strength and creep relaxation,these properties are closely related to the hardening process of concrete,it changes with the development of the age; on the other hand,the external factors,such as the shape of the structural member,the constraint, and ambient temperature and humidity conditions. The stress-strain and temperature development under the condition of concrete early constraints in the actual operation stage are analyzed emphatically. This paper discusses the evaluation of the shrinkage cracking of concrete,deformation cracks,etc. The comments indicate： it is very difficult to solve the cracks in concrete at present. The best technical measures for control are using representational techniques to examine and detect,by increasing the tensile strength,extending the ultimate tensile value and reducing the elastic modulus.