钢管混凝土在标准火灾作用后的粘接性能研究.docVIP

 钢管混凝土在标准火灾作用后的粘接性能 研究# 陶忠1，韩林海2* 5 10 15 20 25 30 35 40 （1. 福州大学土木工程学院，福州 350108； 2. 清华大学土木工程系，北京 100084） 摘要：进行了 64 个在 ISO 标准火灾作用 90 分钟或 180 分钟后的钢管混凝土构件的推出试验， 此外还进行了 12 个未受火的对比构件的试验。试验参数包括：(1)受火时间；(2)截面形式； (3)截面尺寸；(4)界面长度与截面直径或边长的比值；(5)混凝土类型；(6)粉煤灰类型以及 (7)混凝土养护条件。试验结果表明火灾对钢管和混凝土之间的粘接性能有显著影响。在受 火 90 分钟后，粘接强度显著下降；但在受火 180 分钟后，粘接强度又略有恢复。其他因素 对粘接性能也有一定的影响。 关键词：结构工程；钢管混凝土；粘接强度；推出；火灾后 中图分类号：TU398 Post-fire bond between the steel tube and concrete in concrete-filled steel tubular columns TAO Zhong1, Han Linhai2 (1. College of Civil Engineering, Fuzhou University, Fuzhou 350108; 2. Department of Civil Engineering, Tsinghua University, Beijing 100084) Abstract: Push-out tests were carried out on sixty four concrete-filled steel tubular columns, which had been exposed to ISO 834 standard fire for 90 min or 180 min, respectively. At the same time, twelve unheated specimens were also prepared and tested for comparison. The variables investigated in the bond tests were selected as (a) fire exposure time; (b) cross-section type; (c) cross-sectional dimension; (d) interface length to diameter (or width) ratio; (e) concrete type; (f) fly ash type; and (g) concrete curing condition. The effects of the above different parameters on the bond behaviour are discussed. The test results indicate that fire exposure had a significant effect on the bond between a steel tube and its concrete core. A decrease in bond strength was generally observed for specimens after a fire exposure of 90 min; however, bond strength recovery was found when the fire exposure time was extended to 180 min. Other factors also had influence to some extent. Key words: Structural Engineering; Concrete-filled steel tubes; Bond strength; Push-out; Post-fire 0 Introduction Composite columns integrate the favorable characteristics of steel and concrete materials, therefore providing the merits of high strength and stiffness, high speed of construction, large energy dissipation, and considerable economy [1]. For t