免蒸养超高性能混凝土自收缩影响因素研究  

Study on influence of factors on autogenous shrinkage of autoclaving-free ultra high performance concrete

作　　者：丁庆军[1] 张恒[1] 胡俊[1] 耿雪飞 吴文选 辜振睿 DING Qingjun;ZHANG Heng;HU Jun;GENG Xuefei;WU Wenxuan;GU Zhenrui(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China;Wuhan Sanyuan Special Building Materials Co.,Ltd.,Wuhan 430070,China)

机构地区：[1]武汉理工大学硅酸盐工程中心国家重点实验室,湖北武汉430070 [2]武汉三源特种建材有限责任公司,湖北武汉430070

出　　处：《混凝土》2020年第12期1-5,共5页Concrete

基　　金：超高层高强高抗裂预拌混凝土的制备与施工技术(2017YFB0310105);高抗冲磨超高性能水泥基修补材料与应用技术(2018YFC0705404)。

摘　　要：研究了高钛重矿渣砂预湿时间和物化参数、钢纤维掺量、膨胀剂种类和掺量对超高性能混凝土自收缩特性的影响;试验结果表明:延长高钛重矿渣砂预湿时间有助于缓解混凝土内部相对湿度的降低和减小自收缩变形。位于II区且细度模数2.8~3.0的高钛重矿渣砂能明显降低超高性能混凝土自收缩;少量渣粉对超高性能混凝土的自收缩影响较小,当渣粉含量超过一定值后,自收缩变形显著增加。掺入钢纤维能抑制超高性能混凝土自收缩,当纤维掺量超过2.5%时,纤维的限缩效果不明显。FQY型膨胀剂具有较高的膨胀能和十分优异的补偿收缩能力,掺量超过6%时会与基体产生明显的争水效应而导致膨胀效能大幅减弱。The effects of pre-wetting time,physicochemical parameters,steel fiber content,expansive agent types and content on the autogenous shrinkage characteristics of ultra-high performance concrete were studied.The results showed that prolonging the pre-wetting time of high titanium slag sand is helpful to alleviate the decrease of relative humidity and reduce the autogenous shrinkage deformation of concrete.The high-titanium slag sand with a fineness modulus of 2.8~3.0 located in zone II can significantly reduce the autogenous shrinkage of ultra-high performance concrete.Few slag powder has little effect on the autogenous shrinkage of ultra-high performance concrete.When the content of slag powder exceeds a certain value,the autogenous shrinkage deformation increases significantly,steel fiber can inhibit the autogenous shrinkage of ultra-high performance concrete.When the fiber content exceeds 2.5%,the fiber shrinkage effect is not obvious.FQY expansion agent has high expansion energy and excellent compensation shrinkage ability.When the content exceeds 6%,it will produce obvious water competition effect with the substrate,leading to a significant decrease in expansion efficiency.

关 键 词：超高性能混凝土 高钛重矿渣砂 自收缩 内部相对湿度 膨胀剂 

分 类 号：TU528.064[建筑科学—建筑技术科学]