钢筋混凝土T型叠合梁静力性能试验研究

Experimental study on the static behavior of reinforced concrete composite T-beams

本文研究的钢筋混凝土T型叠合梁包括两种,其中叠合梁一由倒T型预制梁、预制板和现浇板组成,叠合梁二由矩形预制梁、预制板和现浇板组成。进行了两种叠合梁及现浇对比梁在单调荷载下的足尺模型试验,对叠合梁的破坏形态、预制梁与预制板之间和预制板与现浇板之间的滑移、截面整体工作性能、正截面受弯承载力与位移延性等进行了研究。研究表明:叠合梁与现浇梁均发生了弯曲破坏;在受力全过程中,叠合梁的截面应变分布满足平截面假定的要求;峰值荷载作用下,叠合梁中实测的预制梁与预制板之间和预制板与现浇板之间的滑移分别小于0.15mm和0.09mm,表明本文采取的叠合面抗剪构造措施是有效的;叠合梁的正截面受弯承载力较相应的现浇梁低4%～12%;3个试件都具有良好的延性特性,其位移延性系数均大于6.0,且叠合梁的位移延性较现浇梁的低1%～15%。研究结果表明,本文研究的两种钢筋混凝土T型叠合梁与现浇对比梁的总体性能均较为接近,均可满足工程设计要求。

Two types of full-scale reinforced concrete composite T-beams are studied： Composite Beam One comprises precast inverted T-beam, precast slab and cast-in-place （CIP） slab, while Composite Beam Two consists of preeast rectangular beam, precast slab and CIP slab. Monotonic tests are conducted on the two types of beams and a CIP control specimen to investigate the failure mode, the slips between precast beam and precast slab, and between precast slab and CIP slab, monolithic action of the entire cross section, positive and negative flexural strengths of normal section and displacement ductility, etc. The results indicated that both of the composite beams and the CIP control specimen failed in bending. Plane section is maintained in the composite beams throughout the testing process. The measured slips between precast beam and precast slab, and between precast slab and CIP slab are less than 0. 15mm and 0. 09mm under the peak load, respectively, revealing the effectiveness of the measures for horizontal shear resistance at the combined interface of composite beams. The flexural strength of normal section of composite beanls is 4% - 12% lower than that of the CIP control specimen. All specimens exhibited good ductility, with the displacement ductility factor larger than 6.0, and the displacement ductility of the composite beanls is about 1% - 15% lower than that of the CIP control specimen. In general, the overall behaviors of the two types of composite beams are similar to those of the CIP control specimen, and can meet the design requirement.