体外预应力竖向张拉法加固钢筋混凝土梁试验研究  

EXPERIMENTAL STUDY ON REINFORCED CONCRETE BEAMS STRENGTHENED BY EXTERNALLY PRESTRESSED VERTICAL TENSIONING METHOD

作　　者：童友枝[1] 朱锦章[1] 

机构地区：[1]湖北工程学院,湖北孝感432000

出　　处：《工业建筑》2012年第6期83-87,共5页Industrial Construction

摘　　要：对7根钢筋混凝土简支梁(2根对比梁、5根加固梁)进行3点加载试验,并通过试验数据,分析了不同张拉控制应力下各梁破坏形态、裂缝开裂情况及受力钢筋、体外预应力筋应变变化规律。试验中采用了加载前施加预应力、加载至开裂卸载施加预应力、加载至开裂不卸载施加预应力3种工况,以模拟实际工程中各种状况。最后,参照各国无粘结预应力筋极限应力理论及基于塑性铰的极限状态理论,研究试验梁的正截面抗弯极限弯矩的计算方法。通过对各国无粘结预应力筋极限应力的计算值对比表明,在二次效应影响较小的情况下,体外预应力结构可采用无粘结预应力结构的研究成果。Seven reinforced concrete beams （two contrast beams and five externally prestressed beams） were tested. The fracture morphology, crack situation, and regularity of changing strain of steel bars and external tendons under different stress of tension control were analyzed through exprerimental data. In order to simulate the conditions of practical projects, there were three kinds of test conditions in the experiment. 1 ） before loading prestress was applied to beam; 2 ）loading to crack, then unloading and prestressing; 3 ） loading to crack, then not unloading and prestressing. Finally, according to ultimate stress theories of unbounded prestressed steel and ultimate condition theory based on plastic hinge, it was studied the caculative method of ultimate bending moment. It was shown that the research achievements of unbounded prestressed structure could also apply to externally prestressed structure when second-order effect was small.

关 键 词：体外预应力 加固 抗弯承载力 

分 类 号：TU375.1[建筑科学—结构工程]