预应力混凝土梁徐变性能试验  

Experiment on Creep Behaviors of Prestressed Concrete Beams

作　　者：薛伟辰[1] 胡于明[1] 王巍[1] 

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《中国公路学报》2008年第4期61-66,共6页China Journal of Highway and Transport

基　　金：建设部研究开发项目(042026);上海市曙光学者计划项目(04SG24);上海市青年科技启明星计划项目(06QH14013)

摘　　要：通过对6根1∶5模型梁的800 d长期试验,对预应力混凝土梁的徐变性能进行了系统的研究,重点考察了混凝土种类、预应力筋张拉方式以及截面上、下缘应力差等因素对梁徐变变形、徐变应变、截面曲率、预应力筋应变和钢筋应力等的影响;基于龄期调整有效模量法,编制了步进法时随有限元分析程序,并应用该程序对试验进行了全过程模拟分析;提出了综合考虑混凝土种类、预应力筋张拉方式以及截面应力差等多因素影响的预应力混凝土梁徐变变形设计建议计算公式。结果表明:有限元分析结果及该设计建议公式计算结果均与试验值吻合较好,且设计建议公式计算结果更为吻合。Experimental and analytical studies were conducted to investigate creep behaviors of six 1 ： 5 scale models of prestressed concrete beams for about 800 d. Influence of concrete type, tensioning pattern of prestressed rebar, stress difference between upper and lower flanges of beam sections on creep deformation, creep strain, cross section curvature, prestressed tendon strain as well as rebar stress of models were investigated. Moreover, based on age adjusted effective modulus method （AEMM）, step by step finite element analysis program used in full range simulation analysis of test was made. Calculated formulae of design suggestions which took concrete type, tensioning pattern of prestressed rebar as well as sectional stress difference between upper and lower fibers into account were put forward. Results show that finite element analysis results and the calculated results of calculated formulae of design suggestions both agree well With test values; the latter agree better with test values.

关 键 词：桥梁工程 预应力混凝土梁 试验研究 徐变性能 时随分析 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]