低周反复荷载下改性再生混凝土框架角节点受力性能试验研究  

EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES OF CORNER JOINTS OF MODIFIED RECYCLED AGGREGATE CONCRETE FRAME UNDER QUASI-STATIC LOADING

作　　者：付佳丽[1,2] 柳炳康 

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]安徽工程大学建筑工程学院,安徽芜湖241000

出　　处：《工业建筑》2018年第1期49-55,11,共8页Industrial Construction

基　　金：安徽省高等教育提升计划项目(TSKJ2015B05);住房与城乡建设部科学技术计划资助项目(2013-K4-46)

摘　　要：对2榀再生混凝土框架顶层角节点进行低周反复荷载试验,其中1榀添加适量粉煤灰等量替代水泥,探讨粉煤灰作为外加剂的改性再生混凝土框架角节点受力性能和变形能力。研究表明：改性再生混凝土角节点的承载能力、破坏形态与未改性再生混凝土差别不大,最终破坏时,节点外侧和柱顶混凝土开裂剥落,表现出较明显的脆性性质。在正、负弯矩的作用下的2榀试件的骨架曲线、刚度退化情况、延性指标和耗能能力基本相同,在张开弯矩作用下添加粉煤灰的试件性能略差。在再生混凝土中添加适量粉煤灰可以改善再生混凝土的耐久性,对于再生混凝土角节点的抗震性能影响不大。GB 50010—2010《混凝土结构设计规范》给出的节点抗剪承载力计算式是根据中节点核心区受剪应力状况导出的,而角节点受力类似折梁受弯,存在较大弯曲成分,有待于进一步研究给出承载力计算式。Two corner joints on recycled concrete frame＇s top story were tested under quasi-static loading,one of which adding appropriate fly ash replacing cement to study the bearing capacity and deformation behavior of corner joints of modified recycled concrete frame. The results showed that the bearing capacity and failure mode of the corner joints of modified recycled concrete frame were little different from those without adding fly ash. The outer of the joint and column top were breaking even spalling which displayed obvious brittleness at final failure. Under the action of positive and negative bending moment, the skeleton curves, stiffness degradation state, ductility and energy dissipation capacity of the two specimens were basically the same; under the action of negative bending moment,the test results of the specimen adding fly ash were slightly worse than the other. The addition of proper amount of fly ash in recycled aggregate concrete could improve the durability of recycled aggregate concrete,which had little effect on the seismic behavior of corner joints. The formula for calculating the shear bearing capacity of joints given by＂Code for design of concrete structures（GB 50010-2010） ＂was based on the condition of shear stress in the core zone of middle joint. However,the stress of corner joints was similar to that of folded beams,where bending should be considered. Further study was needed to obtain a better formula for calculating the bearing capacity of corner joint.

关 键 词：改性再生混凝土 低周反复荷载 顶层角节点 抗震性能 抗剪承载力 

分 类 号：TU37[建筑科学—结构工程]