钢管混凝土偏心受压构件徐变试验  

EXPERIMENTAL RESEARCH ON CREEP OF CONCRETE FILLED STEEL TUBES UNDER ECCENTRIC COMPRESSION

作　　者：赖秀英 陈兆宇 郑娟 LAI Xiuying;CHEN Zhaoyu;ZHENG Juan(College of Civil Engineering,Putian University,Putian 351100,China;College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]莆田学院土木工程学院,福建莆田351100 [2]福州大学土木工程学院,福州350108

出　　处：《工业建筑》2020年第9期139-146,共8页Industrial Construction

基　　金：福建省教育厅中青年教师教育科研项目(JT180474,JT180477);莆田学院引进人才科研启动项目(2018059)。

摘　　要：以偏心率、混凝土强度等级和加载龄期为参数,对2组钢管混凝土偏心受压构件进行徐变试验,并对常用的6种混凝土徐变预测模型进行比较分析。结果表明:随着偏心率的增大,钢管混凝土偏心受压构件最大徐变应变(近载侧)越大,偏心率与徐变应变的关系基本呈线性;混凝土强度等级越高,偏心受压试件的最大徐变应变(近载侧)越小,加载龄期为14 d的C40与C50试件相比较,前者在60,120,180,240 d的徐变应变较后者分别增大了12.2%、26.0%、21.7%和23.7%;加载龄期越早,试件的最大徐变应变就越大,C40的试件,加载龄期14 d在60,120,180,240 d的徐变应变较28 d的分别增大了15.8%、30.1%、21.1%和16.8%。将7个试件及收集的16个试件的徐变实测值与6种常用徐变预测值相比较,结果表明结构用混凝土国际联盟fib MC2010、美国混凝土学会标准ACI 209R-92和欧洲国际混凝土理事会标准CEB-FIP MC90的预测精度较高;fib MC2010预测模型预测精度最高,其平均值和标准差分别为0.992和0.282;其次是ACI209R-92,其两者分别为1.102和0.381;再次是CEB-FIP MC90,其两者分别为1.167和0.327。根据研究结果,建议在结构设计中进行钢管混凝土偏心受压徐变计算时,采用偏安全的徐变终值预测模型。Creep experiments of two groups of CFT eccentric compression members with eccentricity,concrete strength grade and loading age as parameters were carried out.Then 6 commonly used creep prediction models were compared and analyzed.The results from experiment indicated that with the increase of eccentricity,the maximum creep strain(near load side)of CFT eccentric compression members was larger,and the relationship between eccentricity and creep strain was basically linear.The higher the strength grade of concrete was,the smaller the maximum creep strain(near load side)of eccentrically compressed specimens was.Compared with C50 specimens,the creep strain of C40 specimens with loading age of 14 d increased by 12.2%,26.0%,21.7%and 23.7%respectively at 60 d,120 d,180 d and 240 d.The earlier the loading age was,the larger the maximum creep strain was.The creep strain of concrete with strength grade of C40 increased by 15.8%,30.1%,21.1%and 16.8%respectively on the 14th day compared with that on the 28th day at 60 d,120 d,180 d and 240 d.Analytical results indicated that the prediction accuracy of fib MC2010 model,ACI 209R-92 model and CEB-FIP MC90 model was better than that of other prediction models.The prediction accuracy of fib MC2010 model was the best one,the average and standard deviation were 0.992 and 0.282,respectively.The second was ACI 209R-92 model,the two values were 1.102 and 0.381,respectively.The third one was CEB-FIP MC90 model,the two values were 1.167 and 0.327,respectively.According to the results of this paper,it was suggested that,the partial safe prediction model of creep final value could be used for creep calculation of CFT eccentric compression members in the structural design.

关 键 词：钢管混凝土构件 偏心受压 徐变 试验 预测模型 

分 类 号：TU398.9[建筑科学—结构工程]