喷射超高韧性水泥基复合材料的力学性能研究  

Mechanical performance of sprayable Ultra High Toughness Cementitious Composites

作　　者：徐世烺[1,2] 周斌[1] 李庆华[1] 吴宇星[1] 

机构地区：[1]浙江大学高性能建筑结构与材料研究所,浙江杭州310058 [2]杭州固华新材料科技有限公司,浙江杭州311121

出　　处：《水利学报》2015年第5期619-625,共7页Journal of Hydraulic Engineering

基　　金：国家科技支撑计划项目(2012BAJ13B04)

摘　　要：超高韧性水泥基复合材料(Ultra High Toughness Cementitious Composites,UHTCC)是一种具有良好变形性能、裂缝控制能力和耐久性能的新型水泥基复合材料,特别适用于大坝、灌渠等水工结构的加固和修补。然而现有UHTCC材料在喷射施工过程中存在难泵送、易堵管和与结构面粘结性能差等问题,难以实现大面积快速施工,制约了该材料在实际工程中的推广和应用。本文研制出了一种可连续喷射、回弹率低的UHTCC材料,同时保证了喷射过程中纤维的均匀分散,材料硬化后仍具备拉伸应变硬化和多缝开裂特征。喷射UHTCC的压缩性能、直接拉伸性能和抗折性能试验结果显示,该材料28 d龄期抗折强度为10.30 MPa,拉伸强度为2.33 MPa,拉伸应变稳定在1.5%以上,具有延性破坏特征和良好的控裂性能,其性能可满足一般水工结构的表面加固和修补要求。Ultra High Toughness Cementitious Composites （UHTCC for short）, is a kind of high performance fiber reinforced composite with good deformability and crack-controlling ability. Thus, UHTCC is particularly suitable for strengthening and repair of hydraulic structures. However, traditional UHTCC will cause pump difficulty, tube plugging and other coherent problems if using spray method. These problems would limit the material engineering application to some degree. A new design of sprayable UHTCC is intro- duced in this paper, it has several advantages, such as quite low rebound degree, continuously spray pro- cess with seldom tube plugging problems, uniform fiber distribution. Mechanical tests are carried out includ- ing compression test, three-point bending test and direct tension test. The results show that sprayable UHTCC has quite good mechanical properties and retaining multiple crack pattern, which can meet the requirement of hydraulic structures.

关 键 词：超高韧性水泥复合材料 喷射 多缝开裂 应变硬化 

分 类 号：TV544[水利工程—水利水电工程]