混凝土早期约束应力与开裂敏感性研究

Studies on cracking sensitivity and restraint stress of concrete at early ages

混凝土开裂不仅影响到结构的外观和使用性能,还可能对混凝土结构的耐久性产生严重影响。准确地评价混凝土开裂敏感性,是采取有效措施减少或避免开裂的前提。采用单轴约束试验方法,研究了不同温度历程和不同约束程度下混凝土早期约束应力的发展规律,探讨了温度历程对混凝土早期开裂敏感性的影响;研究表明混凝土的临界开裂应力与约束应力的发展历程有关。

Cracking in concrete is destructive not only to appearance and performance, but also to durability of structures.Accurately e- valuation of cracking sensitivity of concrete is the prerequisite for reducing or avoiding cracks effectively in concrete structures.The devel- opment of restraint stress in early-age concrete has been investigated with uniaxial restraint testing method under different thermal and re- straint conditions, and the influence of thermal condition on cracking sensitivity in early-age concrete was analyzed.It was found that the critical cracking stress is affected by stress histories in restraint concrete.