配置高强钢筋的后张有黏结预应力梁短期裂缝试验研究

发布时间：2018-04-13 15:30

本文选题：预应力混凝土梁 + 后张有黏结预应力　；参考：《建筑结构学报》2017年11期

【摘要】：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。
[Abstract]:The flexural behavior tests of 29 post-tensioned prestressed concrete beams with #number0# MPa reinforcement were carried out. The data of 29 groups of crack spacing and 96 groups of short term crack width were obtained.The crack test data of 29 post-tensioned prestressed beams at home and abroad are collected.Based on the above experimental data, the short term crack characteristics of post-tensioned prestressed concrete beams are analyzed, and the applicability of crack calculation formula in GB50010-2010 concrete structure Design Code is evaluated.The results show that the calculation method of short-term crack in code GB50010-2010 is still suitable for post-tensioned prestressed beams with high strength steel bars, and the average crack spacing is calculated according to its formula.The average crack width and the maximum crack width are generally larger than the experimental values, and the average ratio of the two is 1.0861.313 and 1.263 respectively.Therefore, it is suggested that some parameters of the formula of GB 50010-2010 code should be revised, and the calculated crack width should be defined as the center of the outermost draining tensile steel bar on the side of the beam, and the stress of the steel bar should be taken as the stress of the outermost draining tensile steel bar.Through the parameter regression analysis, the modified formula of crack width is obtained, and the conversion formula of crack width between the center of the outermost draining tensile bar on the side of the beam and the center of the tension edge and the center of the prestressed tendons is put forward.The calculated value of the suggested formula is in good agreement with the experimental value.
【作者单位】：同济大学土木工程学院;中国建筑科学研究院;
【基金】：“十三五”国家重点研发计划课题(2016YFC0701903)
【分类号】：TU378.2

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