冻融循环作用下玄武岩纤维网增强混凝土梁弯曲性能试验研究

Experimental study on bending behavior of the basalt textile reinforced concrete beam under freeze-thaw cycles

采用四点弯曲加载的方式研究BTRC梁纤维网层数、Tex含量、冻融循环次数等因素对梁弯曲性能的影响。结果表明:布置纤维网可以提高梁的开裂荷载,但层数和Tex含量的增加对开裂荷载的继续提高影响很小;纤维网层数和Tex含量的增加,均能使BTRC梁的极限承载力和刚度不断提高;随冻融循环次数增加,梁的承载力不断降低,增加纤维网层数和Tex含量可以改善梁的冻融损伤情况,并通过SEM技术探究了冻融循环作用下纤维束与混凝土界面细观结构的变化,解释了冻融循环对纤维编织网增强混凝土的损伤现象。建立了单层纤维编织网的BTRC梁的极限弯矩计算模型,计算值与试验结果吻合得较好,可为相关的工程设计提供参考依据。

By the four-point bend loading mode,the influence of the number of layers,Tex content and freeze-thaw cycle times on the bending behavior of BTRC beams were considered.The results show that the crack load of BTRC beams can be increased by the textile,but the increase of layers and Tex content has little effect on the continuous improvement of crack load.The bearing capacity and stiffness of BTRC beams are improved with the increase of layers and Tex content.With the increase of freeze-thaw cycle times,the bearing capacity decreases.Increasing the number of layers and Tex content can improve the freeze-thaw damage of beams.The meso-structure changes between textile and concrete under freeze-thaw cycles were explored by SEM.The ultimate moment calculation model of BTRC beam with single-layer textile is established.Comparison between the calculated and the experimental results reveals satisfactory agreement,which can provide reference for related engineering design.