预应力型钢超高强混凝土梁受剪承载力试验研究

基于12榀预应力型钢超高强混凝土简支梁和2榀预应力型钢普通强度混凝土简支梁的受剪试验,揭示了影响试验梁受剪性能的主要因素,探讨了剪跨比、箍筋间距、腹板厚度、混凝土强度和预应力度对试验梁的破坏形态、荷载-挠度曲线、斜截面开裂荷载和受剪承载力的影响规律。试验结果表明:预应力型钢超高强混凝土梁具有更好的受剪承载力和剪切延性,以及更大的刚度;基于试验结果建立了预应力型钢超高强混凝土梁的受剪承载力建议计算公式,计算结果与试验结果吻合较好,表明了该文提出的计算公式具有较高的精度。研究成果将为预应力型钢超高强混凝土梁的设计计算和工程应用提供理论依据。

EXPERIMENTAL STUDY ON SHEAR CAPACITY OF PRESTRESSED I-STEEL ULTRAHIGH REINFORCED CONCRETE BEAMS

Based on a shear experiment of 12 prestressed I-steel ultrahigh reinforced concrete beams and 2 prestressed I-steel ordinary reinforced concrete simply supported beams, the main factors affecting the shear performance of a prestressed I-steel ultrahigh reinforced concrete beam were revealed and the influences of the shear span-depth ratio, the space of stirrups, the thickness of web, the compressive strength of concrete and the degree of prestress on the failure mode, the load-deflection curve, the first shear crack load and the shear capacity of test beams were investigated. The experimental results show that prestressed I-steel ultrahigh reinforced concrete beams have better shear capacity and shear ductility, as well as higher stiffness than those of prestressed I-steel ordinary reinforced concrete beams. In addition to the experimental results, a new method for predicting the shear capacity of prestressed I-steel ultrahigh reinforced concrete beams is proposed. The proposed method gives satisfactory predictions as compared to the experimental results. The research achievements are expected to provide a theoretical support for the design calculation and engineering application of prestressed I-steel ultrahigh reinforced concrete beams.