基于等效龄期与结构单元的HPC早龄期拉伸徐变评价  

Evaluation of tensile creep of HPC at early ages based on equivalent age and internal structure

作　　者：杨杨[1] 吴炎平[1] 朱张丰[1] 许四法[1] 

机构地区：[1]浙江工业大学建筑工程学院,杭州310032

出　　处：《东南大学学报（自然科学版）》2010年第A02期165-171,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50979098);浙江省自然科学基金资助项目(Y106856)

摘　　要：通过对早期设计的拉伸徐变装置的改进,实验评价了养护温度和加载龄期对高性能混凝土早龄期拉伸徐变特性的影响.在考虑混凝土内部结构单元对徐变作用的基础上利用流变学原理提出了评价早龄期拉伸徐变的ZC模型.通过对拉伸徐变实验数据的分析,得到了模型参数,进而获得了早龄期拉伸徐变的评价式,并对其进行了实验验证.结果表明,高性能混凝土早龄期拉伸徐变在加载初期增长快速,后期则逐渐趋于稳定,并且养护温度越高,徐变收敛的趋势越明显;所提出的ZC模型能较好地描述不同养护温度和不同加载龄期早龄期拉伸徐变发展特征,对3d前加载的混凝土徐变应变的定量评价其误差在10%以内.The effects of curing temperature and loading age on the behavior of the tensile creep of high performance concrete（HPC） at early ages are experimentally investigated by using improved testing apparatus.An evaluation model（ZC model） on tensile creep,which takes into account the effects of curing temperature,loading age and internal structure of the HPC,is built based on the rheology theory,and a set of the parameters in the models are obtained by fitting a great deal of experimental data.The reliability and precision of the models are verified by means of comparing predict values and experimental data of tensile creep.The results show that the tensile creep stain develops very quickly at the initial of loading and the creep rate decreases rapidly after a short loading time,and the higher the curing temperature,the more remarkable the tendency of convergence in creep rate.The proposed ZC model can be used for describing tensile creep behavior of the HPC under different curing temperatures and loading ages effectively,the error is less than 10% before the loading age of 3d.

关 键 词：拉伸徐变 早龄期 高性能混凝土 评价 等效龄期 

分 类 号：U459.2[建筑科学—桥梁与隧道工程]