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 (1 湖南城市學院土木工程學院， 益陽 413000； 2 湖南大學土木工程學院， 長沙 410082）

［摘要］在恒溫恒濕環(huán)境中對3根素混凝土和3根鋼筋混凝土圓柱進行了500余天收縮徐變試驗，研究了低強（C30及以下）鋼筋混凝土圓柱徐變特性，結(jié)合CEBFIP（1990）模型和中國建科院模型（1986）對實測數(shù)據(jù)進行了擬合回歸分析，計算出不同加載齡期作用下配筋對混凝土徐變的影響系數(shù)，并與采用中國建科院模型（1986）中時變函數(shù)的Dischinger方法進行了對比。試驗結(jié)果表明：相同加載齡期的鋼筋混凝土柱徐變系數(shù)較素混凝土圓柱的偏小，加載齡期對鋼筋混凝土后期徐變系數(shù)影響較少；國內(nèi)外徐變預(yù)測模型對短期加載齡期（9d）的徐變系數(shù)預(yù)測精度較高，對長期加載齡期(39d)的徐變系數(shù)預(yù)測精度較差，特別是對后期徐變系數(shù)預(yù)測普遍不足，GZ（1993）模型整體預(yù)測效果較好；Dischinger方法中鋼筋對低強混凝土徐變影響考慮偏低，對不同加載齡期下鋼筋混凝土徐變變形差值預(yù)測偏低。

［關(guān)鍵詞］鋼筋混凝土圓柱； 徐變系數(shù)； 影響系數(shù)； 試驗研究

中圖分類號：TU528.1      文獻標識碼：A      文章編號：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

*湖南省自然科學基金項目（14JJ4062），湖南省高等學?？茖W研究項目（重點項目）(12A027)。

作者簡介：曹國輝，博士，教授，Email: cgfcivil@163.com。

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