约束变形引起的现浇混凝土结构早期开裂是工程中存在的普遍现象,这种混凝土未成熟期裂缝影响结构的正常使用、耐久性甚至安全性。从材料、结构和施工环境三方面的影响因素出发,对混凝土早期变形裂缝进行综合分析,着重利用裂缝计算的粘结滑移理论,建立轴向配筋构件在约束变形下的开裂机制模型和裂缝参数计算,并对荷载作用和变形作用下裂缝发展以及力学性能的主要特点及差异进行分析比较。
Cracking of concrete caused by early age volume changes such as shrinkage and thermal deformation is always a problem for cast-in-place concrete structures. Such premature cracking affects the serviceability, durability, and even safety of the concrete structure. Integrated analysis is preformed for deformation-caused cracking from the aspects of materials, structures and constructions. Based on the bond-slip theory, cracking mechanism and parameters are analyzed and calculated for the axial restrained reinforced concrete members, and finally the differences in mechanical properties between load-caused and deformation-caused crackings are compared.