Experimental Research On The Flexural Performance And Fracture Property Of Steel Fiber Reinforced Concrete

A number of research work in the steel fiber reinforced concrete(SFRC) have been done in sea and home during the past two decades, and the fundamental theory have been becoming more and more well-rounded. The SFRC have been applied to road, bridge and the lining of tunnel etc which has achieved excellent social economical benefits, the relevant rules have been constituted. But the adoption of SFRC in water-power engineering and hydraulic engineering was late, and it has not been formally used in the concrete faceplate rock-fill dam aside from some small dams mending which have used sprayed SFRC. So, it is necessary to lucubrate if the SFRC could take place the concrete faceplate. That is the background of subject study. The following is the main content of subject study:1. Research the effect of the steel fiber volume ratio on the splitting tensile strength and compressive strength of SFRC through the corresponding experiment of 60 SFRC specimens. The consequence of experiment indicates that the steel fiber volume ratio has no obviously effect on the compressive strength of SFRC; the splitting tensile strength of SFRC increases linearly with the increasing of the steel fiber volume ratio when the steel fiber volume ratio less then or equal to 1 percent.2. Research the effect of the steel fiber volume ratio and length on the flexural ductility of SFRC through the flexural capacity experiment of 72 SFRC specimens which measured the whole effectual curve of load-deflection and calculated the flexural ductility of SFRC. And research the effect of various steel fibers on flexural strength by contrast test. The consequence of experiment indicates that the antifiex cracking strength of SFRC is much higher than common concrete; the flexural ductility of SFRC is improved shapely. According to the consequence of experiment a new method in calculation of flexural ductility of SFRC was put forward which is extreme point deflection toughness exponential method.3. Research the effect of the steel fiber volume ratio and length, aggregate size on the fracture toughness of SFRC and fracture energy of SFRC through the fracture test of 72 SFRC specimens which measured the whole effectual curve of the crack width with the development of load, and calculated the fracture toughness of SFRC and the fracture energy of SFRC. And research the effect of the steel fiber length, the max coarse aggregate size and specimen size on the fracture toughness of SFRC by contrast test. The consequence of experiment indicates that with the increasing of the steel fiber volume ratio, the fracture toughness of SFRC and fracture energy of SFRC have been improved in differently extent.