高速铁路用HRBF500钢筋预应力混凝土梁疲劳性能试验研究

设计制作了2根配置500 MPa细晶粒(HRBF500)钢筋的预应力高强混凝土T形梁,通过实测预应力损失与理论计算比较,得出实测预应力损失大于理论计算值。基于疲劳荷载的试验,绘出HRBF500钢筋应力、钢绞线应力及梁跨中挠度曲线,分析配有细晶粒钢筋的预应力混凝土梁的疲劳性能。结果表明,在一定幅度的疲劳荷载(等幅)作用下,配有HRBF500钢筋的预应力高强混凝土梁,其钢筋、预应力钢绞线及跨中挠度均满足使用阶段规范的限值,即在HRBF500钢筋拉应力大于150 MPa条件下,经过250万次疲劳荷载作用后仍满足设计要求。

THE EXPERIMENTAL RESEARCH ON FATIGUE PERFORMANCE OF PRESTRESSED CONCRETE GIRDER WITH HRBF500 STEEL BAR FOR HIGH SPEED RAILWAY

In this paper,two high-strength prestressed concrete T girders with HRBF500 steel bar have been designed and made.To compare the measured values and the theoretical values of prestress losses,the measured values of prestress losses are more than its theoretical values.Based on the test result under fatigue load,load-stress curves of HRBF500 steel bar and prestressed steel bar and midspan deflection curves of 2 girders are drawn out,and the fatigue performance of high-strength prestressed concrete girder with HRBF500 steel bar is studied.The result shows that HRBF500 steel bar,prestressing strand and midspan deflection in the girders meet the limits of service stage.It also means that the fatigue performance of the prestressed concrete girders with HRBF500 steel bar can still satisfy design requirements after 2.5 millions circles amplitude fatigue loads on the condition that tensile stress of HRBF500 steel bar is more than 150 MPa.