635 MPa 级热轧高强钢筋普通混凝土梁抗剪性能试验研究

为研究 635 MPa 级热轧高强钢筋混凝土梁的抗剪性能,文章选取 9 根试件进行抗剪试验,得到不同参数对试件抗剪承载力的影响规律。结果表明:试件抗剪承载力随着试件剪跨比的减小,混凝土强度、纵筋强度、箍筋强度以及箍筋配箍率的增大而提升;随着试件剪跨比的减小,试件剪切延性会变差,而随着混凝土强度、纵筋和箍筋强度以及箍筋配箍率的增大,试件的剪切延性也随之增强。基于现行规范中钢筋混凝土梁抗剪承载力计算方法,计算 635 MPa 级热轧高强钢筋混凝土梁抗剪承载力,并与试验结果进行对比,结果表明我国规范高估了 635 MPa 高强钢筋混凝土梁的抗剪承载力,但用于设计时仍有一定安全度,而美国规范对高强钢筋混凝土梁抗剪承载力的预测结果偏于保守。在我国规范抗剪承载力计算方法的基础上,考虑纵筋影响和高强箍筋与混凝土匹配性,提出了修正的抗剪承载力计算方法,其计算结果准确度较高。该研究结果为 635 MPa 级高强钢筋混凝土梁在实际工程中的应用提供了理论依据。

In order to study the shear performance of reinforced concrete beams with 635 MPa hot-rolled high-strength steel bars, nine specimens are selected for shear tests and the influence of different parameters on the shear capacity of the specimens is obtained. The research results indicate that the shear capacity of the specimen increases with the decrease of the shear span ratio of the specimen and the increase of the concrete compressive strength, longitudinal reinforcement strength, stirrup strength and stirrup ratio. As the shear span ratio of the specimen decreases, the shear ductility of the specimen will deteriorate; however, as the concrete compressive strength, longitudinal reinforcement strength, stirrup strength and stirrup ratio increase, the shear ductility of the specimen will also increase. The shear capacity of reinforced concrete beams with 635 MPa hot-rolled high-strength steel bars was calculated based on the current specifications and compared with the tested results. It is shown that the Chinese standard overestimates the shear capacity of reinforced concrete beams with 635 MPa high-strength steel bars, but there is still a certain degree of safety when used in design.