【摘要】 为研究冻融循环对砌体结构抗震性能的影响,评估在役砌体结构的抗震能力,对再生混凝土砖墙体进行了冻融循环后低周反复加载试验和有限元模拟分析,对比分析了墙体的破坏过程与特征、承载力与刚度退化、延性、耗能。结果表明:经冻融循环作用后的再生混凝土砖墙体的破坏模式与未经冻融作用墙体略有不同,主要表现为初裂缝出现较早,且发展更为迅速,裂缝多集中于砖块与砂浆的胶结面处,主斜裂缝发展伴有更多的微裂缝出现,破坏程度相对严重;而未经冻融作用墙片裂缝大多沿砖块延伸;随着冻融循环次数的增加,墙体的受剪承载力、刚度、变形与耗能均有所降低;当达到120次冻融循环时,墙体的承载力下降30%左右,初始刚度降低约40%,累计耗能降低约70%,斜向拉伸变形下降80%。更多还原

【Abstract】 Behavior of four recycled concrete brick( RCB) wall models under freeze-thaw cycles was investigated by low cycle reversed loading test and FEA,in order to study on the effect of freeze-thaw cycles on seismic behavior of RCB wall and assess the capacity of existing masonry building. Failure modes of RCB walls were described,meanwhile shear capacity,stiffness,ductility and hysteretic energy were analyzed. It indicates that the failure modes of RCB walls under freeze-thaw cycles are different from intact ones in terms of the earlier occurrence and faster development of cracks. The cracks of walls under freeze-thaw cycles mainly take place in the interface between brick and mortar,especially for the development of main cracks accompanied with more micro-crack and show worse damage. However the cracking of intact walls is in the brick. Shear strength,stiffness,deformation and hysteretic energy of RCB walls decline with the increase of freeze-thaw cycles. The ultimate capacity,initial stiffness,energy dissipation and tensile deformation reduces by over 30%,40%,70% and 80% respectively when freeze-thaw cycles reach 120.更多还原