Experimental Research On The Fundamental Performance Of SFRC And Application In Municipal Works Member

As a new composite material, Steel Fiber Reinforced Concrete(SFRC)is concerned gradually by academic and engineering field universally for its excellent stretching, bending, crack, fatigue resistance and high malleability, etc.. Mixing dispersive steel fiber in concrete can control the development of fracture effectively, and make the composite material resist external force together as a uniform integration.It's a serious problem that the cast iron manhole cover is often stolen in municipal engineering of urban road at present. The manhole cover made of SFRC can solve this problem effectively. It may satisfy the demand of the mechanical performance of manhole cover, and may not be reclaimed as well. It can reduce the potential dangerous of traffic security in great extent.In this paper, the effects of steel fiber on the strength enhancement of concrete are studied based on the experiment of cube crushing strength with 30 test blocks in different volume ratio. The effects of steel fiber on the curvature strength are studied based on the experiment of 30 short test beams. The curvature strength of SFRC is in direct proportion to volume ratio. The enhancement of curvature strength is higher than crushing strength. Incorporating steel fiber in brittle parent material prevents the extending of flaw effectively, changes the damage formation from brittle to plastic.Based on the experiments of 9 SFRC manhole cover with rebar and 3 SFRC cover without rebar, the effects of thickness on rebar-test pieces'strength and fissure and the effects of rebar on test pieces with the same thickness are analyzed. When the thickness of rebar-test pieces are severally 40mm, 60mm and 80mm, their average limit loading capacity can reach 56kN, 122kN and 210kN. As to test pieces without rebar, the average limit capacity can reach 173kN when the thickness is 80mm. It indicates from the test results that SFRC manhole covers with different thickness meet the demand of loading capacity required by different traffic grades. On basis of finite element analogy calculation for manhole cover by ABAQUS, a large-size finite element calculation software, the authenticity of the experiments and the applying feasibility of this technique are verified. The economical benefit and advantage of SFRC manhole cover is analyzed.