高强钢筋钢纤维RPC简支梁受剪承载力试验性能研究

为了探究RPC简支梁受剪承载力的影响性能,通过对6根2组剪跨比为2.25和3.0的矩形梁进行受剪性能试验,分析2组不同剪跨比的试验梁,其配箍率对受剪承载力的影响;将试验结果与普通钢筋混凝土修正压力场公式,以及我国规范公式的计算结果进行对比分析;考虑配箍率与钢纤维的影响,修正RPC主拉应力-应变本构关系,并编制程序进行迭代计算,得出钢纤维对承载力的贡献率。研究发现:配箍率和剪跨比对试验梁承载力的影响均比较明显。配箍率≤0.252%时,配箍率越大,试验梁的受剪承载力越大,但随着配箍率的继续增大,试验梁呈弯剪破坏趋势,配箍率-荷载曲线趋于平缓;钢纤维对RPC梁抗剪承载力的影响不容忽视,而且对无腹筋梁的影响大于有腹筋梁;基于修正压力场理论模型的改进计算程序用于计算高强钢筋RPC梁的抗剪承载力,其理论值与试验值吻合良好,具有一定的可信度和实用性。

Experimental Study on Shear Bearing Capacity of RPC Beams with High Strength Reinforcement and Steel Fiber

In order to explore the influence of shear bearing capacity of RPC beams,6 rectangular beams with two groups of shear span ratio 2. 25 and 3. 0 are used to study their shear performances. The test results are analyzed and compared with the computed results of MCFT and China's relevant specification of arithmetic. With the effect of stirrup ratio and the steel fiber considered,the constitutive relation of RPC tensile stress-strain is modified and a program is written for iterative calculation to obtain the bearing capacity contribution rate of steel fiber. The study finds that the influence of stirrup ratio and shear span ratio are obvious on the bearing capacity of beams. When the stirrup ratio is less then 0. 252,the higher the stirrup ratio,the greater the shear bearing capacity of test beams. But with the stirrup ratio continuing to increase,test beams tend to suffer bending shear failure,and the curve of stirrup ratio-load tends to be gentle. The influencegenerated by steel fiber on the shear bearing capacity should not be ignored,and the influence on the beams without stirrups is greater than that on the beams with stirrups. When the improved calculation program based on the calculation model of MCFT is used to calculate the shear capacity of high strength reinforced RPC beams,its theoretical calculation values coincide well with the test results,and prove to have certain reliability and practicality.