铁路工程应用高强钢筋后裂缝宽度计算试验研究

Experimental Research on Crack Width Calculation of RC Beams with High-strength Rebars for Railway Engineering

为了研究高强钢筋对铁路桥涵混凝土构件裂缝宽度计算的影响,并验证文献[2]裂缝计算的适用性,对36根配置高强钢筋的混凝土构件进行了试验研究,通过32根构件的静载受弯试验和4根构件的重复荷载试验对该类构件的裂缝变化情况进行了观测和记录,结合收集到的部分同类试验数据,对构件的裂缝宽度计算进行了统计分析。试验结果表明:该类构件裂缝开展情况同普通钢筋混凝土构件一致,疲劳荷载作用下构件的裂缝宽度则随着重复加载次数的增加而增加,初期增长较快,后期趋于稳定,但是该类构件的裂缝宽度实测值与文献[2]计算存在一定偏差,利用收集到的高强钢筋裂缝数据对文献[2]中裂缝计算进行重新修正,提出的公式适用性良好,可以作为铁路工程应用高强钢筋裂缝计算的参考。

Thirty-six RC beams with high-strength rebars,including thirty-two beams for static loading test and four beams for fatigue test,were tested to study the influence of high-strength rebars on the calculation of crack width of concrete members of railway bridges and culverts,and check the applicability of the calculation formulas of cracks given by literature[2].The development of the cracks in the tests was observed and recorded.The crack calculation of the RC beams with high-strength rebars was analyzed according to the crack data collected from the test and other similar tests.The results show that the development of the cracks of the RC beams under short-term static loading test is the same as that of normal rebars.The crack width under fatigue test increases with the cycle number of load,with faster growth in the initial stage and stable growth in the later stage.However,a certain deviation exists between the tested values of the crack width of the RC beams and the calculated values of literature[2].According to the experimental data collected from the test and other similar tests,the crack calculation in the literature[2]is corrected and the proposed calculation formula can work well with the tests and can be used as a reference for crack calculation of RC beams with high-strength rebars in railway engineering.