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进行了29根配置500 MPa级钢筋的后张有黏结预应力混凝土梁的受弯性能试验,获得了29组裂缝间距和96组短期裂缝宽度数据;收集了国内外29根后张有黏结预应力梁的裂缝试验数据。采用以上试验数据,分析了后张有黏结预应力混凝土梁的短期裂缝特征,并评估了GB 50010—2010《混凝土结构设计规范》中裂缝计算公式的适用性。研究结果表明:规范GB 50010—2010的短期裂缝计算方法仍适用于配置高强钢筋的后张有黏结预应力梁,按其公式计算的平均裂缝间距、平均裂缝宽度和最大裂缝宽度较试验值普遍偏大,二者之比的均值分别为1.086、1.313和1.263。因此,建议对GB 50010—2010规范公式部分参数进行修正,并建议将计算裂缝宽度明确为梁侧面最外排受拉钢筋中心处、钢筋应力取为最外排受拉钢筋的应力。通过参数回归分析,得到裂缝宽度的修正计算公式,并提出梁侧面最外排受拉钢筋中心处与受拉边缘、预应力筋中心处的裂缝宽度的换算关系式,建议公式的计算值和试验值符合较好。
29 bending tests of 29 post-tensioned bonded prestressed concrete beams with 500 MPa steel bars were carried out, and 29 sets of crack spacing and 96 sets of short-term crack width data were obtained. Twenty-nine post-tensioned bonded prestressed Beam crack test data. Based on the above experimental data, the short-term fracture characteristics of post-tensioned prestressed concrete beams are analyzed, and the applicability of the crack formula in Concrete Structure Design Code GB 50010-2010 is evaluated. The results show that the calculation method of short-term cracks in GB 50010-2010 is still applicable to the post-tensioned prestressed composite beams with high-strength reinforcement. The average crack spacing, the average crack width and the maximum crack width calculated according to the formulas are generally lower than the experimental values Large, the average ratio between the two were 1.086,1.313 and 1.263. Therefore, it is suggested to amend some of the parameters in the formula of GB 50010-2010, and it is suggested that the crack width should be calculated as the center of the outermost row of tensile beam in the side of the beam, and the stress of the reinforcement should be taken as the stress of the outermost row of tensile reinforcement. Through the regression analysis of the parameters, the correction formula of the crack width is obtained, and the conversion formula of the crack width at the center of the outermost row of tensile beam and the tension edge and the prestressing tendon is proposed. The calculated value and test of the proposed formula Value in line with better.