装配式建筑组合叠合梁抗弯性能试验研究

Experimental Study on Flexural Performance of Prefabricated Building Composite Laminated Beams

以三亚城投大厦项目装配式建筑叠合梁为研究对象,运用室内物理模拟试验的方法,制作了9种不同类型的叠合梁,分析UHPC-NC叠合梁的荷载-挠度、开裂荷载与极限承载力的变化特征,研究UHPC叠合高度、UHPC叠合位置、纵筋配筋率和钢纤维类型等因素对叠合梁受弯性能的影响。研究结果表明:UHPC-NC叠合梁的荷载-跨中挠度曲线有弹性阶段、裂缝开展阶段和破坏阶段3个阶段;UHPC-NC叠合梁具有良好的挠度延性、抗裂性能和刚度储备,其最终挠度与屈服挠度之比为2.82~7.42;在剪跨段,斜裂缝的分布表明UHPC的存在对阻止叠合梁斜裂缝的发展和提高抗剪承载力具有积极的影响;纵筋配筋率越高,屈服弯矩和极限弯矩越大;在相同钢纤维体积掺量下,叠合梁的屈服弯矩显著效果依次为端勾、波纹与平直。

Based on the prefabricated building laminated beam of Sanya City Investment Building project as the research object,nine different types of laminated beams are made by using the method of indoor physical simulation test.Then,the variation characteristics of load-deflection,cracking load and ultimate bearing capacity of UHPC-NC laminated beams are analyzed.The effects of UHPC laminated height,UHPC laminated position,longitudinal reinforcement ratio and steel fiber type on the flexural performance of laminated beams are studied.The results show that:The load-mid-span deflection curve of UHPC-NC laminated beam has three stages:elastic stage,crack development stage and failure stage;UHPC-NC laminated beams have good deflection ductility,crack resistance and stiffness reserve,and the ratio of final deflection to yield deflection is 2.82~7.42;In the shear span section,the distribution of oblique cracks shows that the existence of UHPC has a positive effect on preventing the development of oblique cracks of laminated beams and improving the shear capacity;The higher the longitudinal reinforcement ratio,the greater the yield bending moment and ultimate bending moment.Given the same volume content of steel fiber,the significant effect of yield bending moment of laminated beam is the order of end hook,ripple and straight.