硅灰对钢纤维-水泥石界面黏结强度影响

发布时间：2018-08-03 15:19

【摘要】：通过自制模具实现了对钢纤维从水泥石基体中拔出的实验测试,得到基体混凝土中钢纤维体积掺量为0~1.2%、硅灰取代水泥质量掺量为0~12%时钢纤维拉拔荷载-位移曲线图,通过显微硬度和SEM试验,测试得到了钢纤维-水泥石界面纤维硬度及界面区微观形貌特征。在测试基础上,提出了界面黏结拉拔韧性概念,并计算得到了界面黏结强度和拉拔韧性,分析了硅灰对界面黏结强度、拉拔韧性、界面显微硬度和微观形貌特征的影响规律。研究结果表明,硅灰改善了钢纤维-水泥石界面黏结性能,使界面黏结强度提高了10.7%~44.2%;界面区显微硬度提高了7.4%~38.8%,界面最薄弱层与钢纤维表面的距离由普通混凝土的60μm缩小到40μm,且硅灰掺量越大,效果越好;硅灰使钢纤维拉拔时峰值荷载对应的位移下降了4.1%~25.9%;对于不同掺量的钢纤维混凝土,钢纤维拔出韧性的最佳硅灰掺量为6%~9%。
[Abstract]:The experimental test of steel fiber pulling out from cement stone base was realized by self-made mould. The drawing load-displacement curve of steel fiber was obtained when the volume of steel fiber in matrix concrete was 0 ~ 1.2, and the mass content of silica fume replaced cement was 0 ~ 12, the drawing load displacement curve of steel fiber was obtained. The microhardness and micromorphology of the interface between steel fiber and cement stone were obtained by microhardness and SEM test. On the basis of testing, the concept of interfacial bond drawing toughness is put forward, and the interfacial bond strength and drawing toughness are calculated. The influence of silica fume on interfacial bonding strength, drawing toughness, interface microhardness and micromorphology is analyzed. The results show that silica fume can improve the interfacial bonding properties of steel fiber and cement stone. The interfacial bonding strength is increased by 10.7 and 44.2.The microhardness of the interface area is increased by 7.4and 38.8.The distance between the weakest layer of interface and the surface of steel fiber is reduced from 60 渭 m of ordinary concrete to 40 渭 m, and the greater the content of silica fume is, the better the effect is. Silica fume reduces the displacement corresponding to the peak load of steel fiber drawing by 4.1and 25.9.The optimum silicon fume content of steel fiber pull-out toughness is 6 / 9for steel fiber concrete with different content.
【作者单位】：重庆交通大学材料科学与工程学院;重庆交通大学重庆西南水运科学研究所;广西交通科学研究院;
【基金】：交通运输部应用基础研究项目(2013319814060) 重庆市科委攻关项目(2011GGC006)
【分类号】：U414

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