摘要
混凝土的早期力学性能对于结构施工期的安全性具有重要影响。为了探讨再生混凝土结构的施工措施,保证其施工质量和安全性,系统研究了再生混凝土的早期力学性能,主要包括抗压强度、劈裂抗拉强度和弹性模量以及收缩。试验中共考虑了3种强度等级(C20、C30和C40),在龄期分别为1、3、7、14、21、28d时进行试验。比较了再生混凝土和普通混凝土早期力学性能随时间发展规律的差异,探讨了普通混凝土早期力学性能计算公式对再生混凝土的适用性试。试验结果表明,再生混凝土的早期强度和弹性模量随时间发展较普通混凝土慢,而收缩的发展速度则与普通混凝土相差不多,但其绝对收缩值有显著增加。为保证再生混凝土结构施工的安全性,需要在施工期间采取相应措施。普通混凝土早期力学性能计算公式不适用于再生混凝土,基于试验结果,建议了再生混凝土早期力学性能计算方法。
The mechanical properties of concrete at early ages are very important for the safety during the construction period.In order to assure the construction safety of recycled aggregate concrete ,the mechanical properties at early ages were investigated, including the compressive strength, the tensile splitting strength, the modulus of elasticity and the shrinkage.In the test, three strength grades, i.e., C20, C30 and C40 were included at the age of 1,3,7,14,21 d and 28 d.The difference in the development of the early age properties of recycled aggregate concrete and conventional concrete was compared.The suitability of using the equations for the early age mechanical properties of conventional concrete to recycled aggregate concrete was examined.The test results indicated that the developments of the strength and elastic modulus of recycled aggregate concrete are generally slower than that of conventional concrete, while the development of shrinkage is comparable to that of conventional concrete, however with a much larger absolute shrinkage value.This should be carefully considered in the construction using.The equations for the mechanical properties of conventional concrete at early ages are not applicable for recycled aggregate concrete.Alternative equations for recycled aggregate concrete were developed based on the regression analysis of the test results.
出处
《混凝土》
CAS
CSCD
北大核心
2008年第5期37-41,共5页
Concrete
关键词
再生混凝土
早期力学性能
强度
弹性模量
收缩
recycled aggregate concrete
mechanical properties at early ages
strength
modulus of elasticity
shrinkage
