轻质超高性能混凝土的设计与研究  

Research on preparation and performance of lightweight ultra high performance concrete

作　　者：丁庆军[1] 胡俊[1] 刘勇强[1] 彭程康琰 张高展 DING Qingjun;HU Jun;LIU Yongqiang;PENG Chengkangyan;ZHANG Gaozhan(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China;School of Materials and Chemical Engineering,Anhui Jianzhu University,Hefei 230601,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]安徽建筑大学材料与化学工程学院,安徽合肥230601

出　　处：《混凝土》2019年第9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);国家自然科学基金资助(51878003)

摘　　要：研究了胶凝材料组成、胶砂比以及钢纤维掺量对轻质超高性能混凝土(LUHPC)工作性能与力学性能的影响,得出LUHPC最优配合比,提出了LUHPC设计制备方法;对比研究了普通超高性能混凝土(UHPC)与LUHPC的力学性能与体积稳定性能差异;采用SEM-EDS和显微硬度计分析了LUHPC水泥石以及轻集料界面微结构特征。结果表明:水泥、粉煤灰微珠和硅灰用量分别为804、204、192 kg/m3,水胶比0.18,胶砂比1.8,钢纤维体积掺量为2.5%时,LUHPC工作性能优异,具有良好的轻质、高强、低收缩性能;相比UHPC,LUHPC比强度更高,体积稳定性优良;陶砂的“缓释水”作用可使界面处胶凝材料后期持续水化,改善界面处微结构,降低混凝土自收缩。The effect of the composition of cementitious materials,the ratio of cement to sand and the content of steel fiber on the working performance and mechanical properties of lightweight ultra high performance concrete(LUHPC)was studied.The optimum mixture ratio of LUHPC was obtained,and the design and preparation method of LUHPC was put forward.The difference between the mechanical properties and the volume stability of UHPC and LUHPC was compared and studied.The microstructure characteristics of the interface of the LUHPC cement paste and the light aggregate were analyzed by SEM-EDS and microhardness.The result showed that when cement,fly ash microsphere and silica fume were 804,204 and 192 kg/m3 respectively,binder-sand ratio is 1.8,water cement ratio is 0.18 and the volume of steel fiber volume is 2.5%.The performance of LUHPC is excellent,and it also have low apparent density,high strength and low shrinkage performance.Compared with UHPC,LUHPC have higher specific strength and excellent volume stability.The“slow release water”of pottery sand can make the cementing material at the interface continue to hydrate at the later stage,improving the microstructure at the interface,and reducing the autogenous shrinkage of the concrete.

关 键 词：轻质超高性能混凝土 陶砂 力学性能 体积稳定性 界面微结构 

分 类 号：TU528.02[建筑科学—建筑技术科学]