Shear Capacity Analysis of Steel Reinforced Lightweight Concrete Elements Based on The Bond Strength

Abstract

Push-out tests of steel reinforced lightweight concrete(SRLC) were carried out for nine specimens which were designed according to the orthogonal test method considering four influence factors including strength of lightweight aggregate concrete, stirrup ratio, thickness of protective layer and anchorage length. The curves of average bond stress and loading-end slip were drawn, the characteristics of split failure and push-out failure were analyzed, and the characteristic bond strength was obtained. Combined with the test results of other scholars on the ultimate bond strength of steel reinforced concrete(SRC), it is found that the bond strength of SRLC is not worse than that of normal concrete(NC) which can be taken the same as 0.5MPa. Then the obtained bond strength can be used to calculate the shear strength of SRLC elements which may occur two forms of shear failure-diagonal shear failure and shear bond failure, however, shear bond failure is ignored in some specifications. Shear bond failure capacity computational formula of SRLC elements is deduced into which the bond strength is introduced.To verify the reasonability and accuracy of the proposed approach, the shear capacity and failure pattern are predicted by the proposed means with previous test results and are also compared with other provisions. The analyses and calculations indicate that the proposed method can accurately predict the shear failure mode and the calculated shear capacity values are in better agreement with the experimental results.