摘要
采用绝热和温度匹配(TMC)2种温度历程养护模式,进行基准混凝土(F35混凝土)和超高掺量粉煤灰大坝混凝土(F80混凝土)的温度—应力试验(TST)。由实测的2种温度历程下的自由试件的应变获得大坝混凝土热膨胀系数和温度变形规律,进而得到2种大坝混凝土的自收缩变形规律。分析2种大坝混凝土的自收缩变形规律,提出大坝混凝土变温自收缩变形模型。结果表明:大坝混凝土的早龄期自收缩变形具有时变性,温度历程影响自收缩变形的发展。对于同种混凝土,绝热模式下自收缩变形大于温度匹配模式下的自收缩变形;F80混凝土的早龄期自收缩变形明显小于F35混凝土。提出的早龄期变温自收缩变形模型可较好地预测大坝混凝土的早龄期自收缩变形发展。
Temperature stress tests(TST)are conducted on a reference dam concrete(F35 concrete)and dam concrete(F80 concrete)with ultra-high fly ash content under the adiabatic curing mode and the TMC curing mode.From the strains in free specimens measured by TST under the two curing modes,the thermal expansion coefficient and thermal deformations are obtained and the autogenous shrinkage of dam concrete is separated successfully.The developments of autogenous shrinkage of dam concrete are analyzed.An autogenous shrinkage model of dam concrete at early ages under variable curing temperature is proposed.The results show that the autogenous shrinkage of dam concrete at early ages is time dependent and affected by the curing temperature history.For a given concrete,the autogenous shrinkage under the adiabatic mode is larger than that under the TMC mode.The autogenous shrinkage of F80 concrete at early ages is significantly smaller than that of F35 concrete.The proposed autogenous shrinkage model of early age dam concrete under variable temperatures can predict the development of early-age autogenous shrinkage of dam concrete accurately.
作者
赵志方
徐乐靓
鹿永久
章宦秘
赵志刚
ZHAO Zhifang;XU Lejing;LU Yongjiu;ZHANG Huanmi;ZHAO Zhigang(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China;China Three Gorges Corporation LTD Test Center,Wudongde Engineering Sub-center,Kunming 651500,China;Communication University of Zhejiang,Hangzhou 310018,China)
出处
《浙江工业大学学报》
CAS
北大核心
2021年第6期636-641,共6页
Journal of Zhejiang University of Technology
基金
国家自然科学基金资助项目(51879235
51479178)。
