折线先张预应力混凝土梁徐变试验研究  

Experimental Study on Creep of the Prestressed Concrete Beams with Pretensioned Bent-up Tendons

作　　者：王俊[1,2] 刘立新[1] 何盛东[1] 

机构地区：[1]郑州大学土木工程学院,郑州450001 [2]许昌学院城市与环境学院,河南许昌461000

出　　处：《建筑科学》2010年第9期7-10,共4页Building Science

基　　金：国家自然科学基金资助项目(50574148);河南省交通厅资助项目(2005P338)

摘　　要：通过对二根置于标准条件、一根置于室外自然环境的7.5m跨的折线先张预应力混凝土简支梁进行长期加载,定时观测了试验梁跨中截面上边缘和下部纵向非预应力筋高度处的弯曲应变徐变情况,得出了折线先张梁徐变和徐变系数时程曲线及其变化规律。通过对试验梁徐变系数试验值采用Datafit软件进行数学处理,得出了试验梁徐变系数时程曲线的拟合公式,并与ACI209R-92、CEB-FIP MC90及我国86成果等规范对试验梁的徐变系数计算结果进行了对比,分析了各规范对试验梁在进行徐变系数预测时的误差情况。结合我国86成果的"多系数法",提出了以试验数据为基础、基于折线先张梁工程应用的徐变系数计算公式。Three simple supported prestress concrete beams with 7.5m in span were pretension by using bent-up tendons,two of them were placed in standard indoor curing environment and other one was placed outdoors.These beams were tested under long term loading,and the creep data in different time were obtained and the time-history curves of the creep coefficients in midspan section,were drawn.Utilizing DATAFIT software,Creep coefficient equation of the test beams was fit and compared with the code models such as ACI209R-92,CEB-FIP MC90 and ‘86 model’proposed by China Academy of Building Research.Combining the ‘86 model’with the test results,the calculation formula of the creep coefficients is put forward,which may be providing to engineering practice for

关 键 词：折线先张预应力混凝土梁 长期加载 徐变 徐变系数 

分 类 号：TU378.2[建筑科学—结构工程] U448.217[建筑科学—桥梁与隧道工程]