硅灰改性高韧性水泥基材料性能试验研究  

Emperimental study on high toughness cement-based materials modified by silica fume

作　　者：李晓琴[1] 周旭[1] 李世华 刘国寿[1] LI Xiaoqin;ZHOU Xu;LI Shihua;LIU Guoshou(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650500,P.R.China;Yunnan Construction Investment Green High-Performance Concrete Co.,Ltd,Kunming 650500,P.R.China)

机构地区：[1]昆明理工大学建筑工程学院,昆明650500 [2]云南建投绿色高性能混凝土股份有限公司,昆明650500

出　　处：《土木与环境工程学报（中英文）》2022年第6期170-180,共11页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51968035);云南省教育厅科学研究基金(2019J0043);云南省重点研发计划项目(202003AC100001);云南省交通厅科技基金(2017A-04);昆明理工大学分析测试基金(2018M20182210048)。

摘　　要：工程水泥复合材料(ECC)具有良好的韧性和裂缝控制能力,可用于解决地下和水工工程中的混凝土开裂和渗漏水问题。高水灰比ECC(w/c=1.03)流动度好,但抗渗性能差,且水灰比过高使得材料坍落度大、黏聚性差,不满足可喷射性的指标要求。为了解决上述问题,将硅灰(SF)以不同的SF/水泥质量比引入高水灰比ECC中,以改善其工作性能、抗渗性能、微观结构和力学性能。结果表明,当SF/水泥比为15%时,高水灰比ECC的工作性能大大提高,达到新拌材料可泵送及可喷射的指标要求,高水灰比ECC的抗渗性能提高至P8以上;扫描电镜(SEM)和能量分散光谱仪(EDS)的观察结果证实,添加SF使ECC的显微组织更致密,而且还可以减少碱性物质的产生,从而抑制碱集料反应,提高耐久性。对ECC展开韧性、抗渗性及工作性能(可泵送及可喷涂)研究,获得了高韧性、高抗渗、可喷可泵的ECC配合比,为其在实际工程中的推广及应用奠定了基础。Engineering cementitious composites(ECC)have excellent toughness and crack control ability,which can be used in underground and hydraulic engineering solving the problems of concrete cracking and leakage.ECC with high water-cement ratio(w/c=1.03)has excellent fluidity,but its impermeability is poor.Meanwhile,the high water-cement ratio also induces large slump and poor cohesiveness,leading poor sprayable abilities.In order to solve the above problems,silica fume(SF)was then introduced into ECC(w/c=1.03)with different SF/cement mass ratios to improve its workability,impermeability,microstructure and mechanical behavior.The results indicate that when SF/cement ratio was 15%,the workability of ECC with high water-cement ratio was greatly improved,which could be pumped and sprayed.At the same time,the impermeability of ECC with high water-cement ratio is improved to above P8.The scanning electron microscope(SEM)and energy dispersive spectrometer(EDS)observations confirmed that adding SF made ECC microstructures denser,but also could reduce the alkaline substances to inhibit alkali-aggregate reaction and improve durability.Through the study of toughness,impermeability and workability(pumpable and sprayable)of ECC,the mix proportion of ECC with high toughness,high impermeability,spraying and pumping was obtained,which laid a foundation for the popularization and application in practical engineering.

关 键 词：工程水泥复合材料 高韧性 工作性能 抗渗性 微观结构 硅灰 

分 类 号：TU528.32[建筑科学—建筑技术科学]