(1 湖南城市学院土木工程学院， 益阳 413000； 2 湖南大学土木工程学院， 长沙 410082）

［摘要］在恒温恒湿环境中对3根素混凝土和3根钢筋混凝土圆柱进行了500余天收缩徐变试验，研究了低强（C30及以下）钢筋混凝土圆柱徐变特性，结合CEBFIP（1990）模型和中国建科院模型（1986）对实测数据进行了拟合回归分析，计算出不同加载龄期作用下配筋对混凝土徐变的影响系数，并与采用中国建科院模型（1986）中时变函数的Dischinger方法进行了对比。试验结果表明：相同加载龄期的钢筋混凝土柱徐变系数较素混凝土圆柱的偏小，加载龄期对钢筋混凝土后期徐变系数影响较少；国内外徐变预测模型对短期加载龄期（9d）的徐变系数预测精度较高，对长期加载龄期(39d)的徐变系数预测精度较差，特别是对后期徐变系数预测普遍不足，GZ（1993）模型整体预测效果较好；Dischinger方法中钢筋对低强混凝土徐变影响考虑偏低，对不同加载龄期下钢筋混凝土徐变变形差值预测偏低。

［关键词］钢筋混凝土圆柱； 徐变系数； 影响系数； 试验研究

中图分类号：TU528.1      文献标识码：A      文章编号：1002-848X(2015)08-0054-05

Influence of reinforcement on longterm creep of concrete circular column

Cao Guohui1, Hu Jiaxing2, Zhang Kai1

 (1 College of Civil Engineering, Hunan City University, Yiyang 413000, China;

2 College of Civil Engineering, Hunan University, Changsha 410082, China)

Abstract:Through longterm test of the shrinkage creep for 3 reinforced concrete  circular columns and 3 plain concrete circular columns with more than 500 days in the constant temperature and humidity environment, research on creep properties of reinforced concrete columns for low intensity concrete(the cube compressive strength within 28d is less than or equal C30), the measured data were fitted by regression analyses combined with the models of CEBFIP（1990）and  China Institute of Building（1986）to calculate influence coefficient of concrete creep caused by reinforcement in the different loading ages and compare with the Dischinger method in  timedependent function used China Institute of Building model（1986）.  Test result shows that the creep coefficient of reinforced concrete is less than that of  plain concrete in the same loading age, and the loading age has little influence on reinforced concrete creep coefficient in later stage. The creep prediction models at home and abroad have high predictive accuracy for creep coefficient with shortterm loading age (9d) but little predictive accuracy for creep coefficient with longterm loading age(39d), especially that predicted values of creep coefficient are general insufficient in late stage. The predictive effect of GZ (1993) model is best. In Dischinger method, the reinforcement influence on  creep of low intensity concrete is insufficiently considered, and creep deformation differences of reinforced concrete under different loading ages is insufficiently predicted as well.

Keywords:reinforced concrete circular column; creep coefficient; influence coefficient; experimental study

*湖南省自然科学基金项目（14JJ4062），湖南省高等学校科学研究项目（重点项目）(12A027)。

作者简介：曹国辉，博士，教授，Email: cgfcivil@163.com。

                            参考文献

［1］杨小兵.混凝土收缩徐变预测模型研究［D］.武汉:武汉大学, 2004.

［2］林波.混凝土收缩徐变及其效应的计算分析和试验研究［D］.南京:东南大学, 2004.

［3］张克波, 许康, 吕毅, 等.配筋混凝土柱徐变试验［J］.长沙理工大学学报：自然科学版, 2011, 8(2):1720.

［4］曹国辉, 胡佳星, 张锴, 等.混凝土徐变预测模型修正分析［J］.建筑结构, 2014, 44(5):4549.

［5］周履, 陈永春. 收缩徐变［M］.北京:中国铁道出版社, 1994.

［6］BAZANT Z P, MURPHY W E. Creep and shrinkage prediction model for analysis and design of concrete structuresmodel B3 ［J］. Material and Structures, 1995(28): 357365.

［7］GARDNER N J,  ZHAO J W. Creep and shrinkage revisited ［J］. ACI Materials Journal, 1993, 90(3): 236246.

［8］JTG D62—2004 公路钢筋混凝土及预应力混凝土桥涵设计规范［S］. 北京: 人民交通出版社, 2004.

［9］龚洛书, 惠满印, 杨蓓. 砼收缩与徐变的实用数学表达式［J］.建筑结构学报, 1988，5(5): 3742.

［10］GARDNER N J,  LOCKMAN M J. Design provisions for drying shrinkage and creep of normalstrength concrete ［J］. ACI Materials Journal, 2001, 98(2): 159167.

［11］傅学怡, 高洪.钢筋混凝土柱收缩徐变分析［J］.建筑结构学报, 2009 (增刊1)：191194.

［12］金成棣.混凝土徐变对超静定结构变形及内力的影响—考虑分段加载龄期差异及延迟弹性影响［J］.土木工程学报, 1981, 14(3):1933.

［13］方辉.高层混凝土结构考虑施工过程和混凝土徐变收缩影响的分析［D］.长沙:湖南大学, 2006.