The influence of steel fiber shape and volume fraction on the working perfomance and mechanical properties of ultra-high performance concrete(UHPC)was comparatively researched,and SEM method was used to reveal its evolution mechanism.The results show that with the gradual increase of steel fiber content,the working performance of UHPC gradually deteriorates,and the end hook steel fiber has the most significant effect on the deterioration of working performance.When the volume fraction of steel fibers is 1.5％～2.5％,the compressive strength,flexural strength,and splitting tensile strength of end hook type and long straight line type steel fiber UHPC are the best..When the volume fraction of steel fibers is 1.5％～2.0％,the mechanical and working properties of short linear steel fiber UHPC are the best.Through SEM analysis,it was found that steel fibers are distributed in a staggered and continuous manner in the matrix,easily forming a three-dimensional network structure,which can prevent the generation of macroscopic cracks and the development of microcracks,and enable UHPC to exhibit good mechanical properties.
维普
万方数据