摘要
高性能复合砂浆钢筋网薄层(简称HPFL)加固混凝土构件是一种新型的加固方法,为研究其高温性能,对7根三面U型(在梁的受拉面和侧面进行加固)加固梁和1根未加固对比梁从加固界面原混凝土表面粗糙度、初始荷载两个方面进行了高温抗剪试验研究。试验结果表明,在初始荷载一定的条件下,加固界面为Ⅰ级粗糙度的试件耐火时间较短,出现了加固层剥离退出工作的现象,Ⅱ级粗糙度、Ⅲ级粗糙度试件的耐火时间显著延长,且均为整体破坏,说明当加固界面为Ⅱ级、Ⅲ级粗糙度时能显著提高试件的耐高温性能。在界面粗糙度等级相同的条件下,随着初始荷载的增加,加固梁的耐火性能迅速下降。
High-performance ferrocement laminate （HPFL） is a new type of method for retrofitting RC component. In order to investigate its high-temperature behavior, an experiment program was carried out, which included seven RC beams strengthened with U-shaped （ferrocement was put onto the tension face and two profile faces） and a reference RC beam. The objective of the research was to find out shear resistance at high-temperature from the perspective of interface roughness and initial load. The results of the experiment illustrate that under the condition of fixed initial load, the fire resistance of the reinforcement layer with grade Ⅰ interface roughness was very short, with early spalling of the retrofit layer, whereas the fire resisting time of specimens with grade Ⅱ and Ⅲ interface roughness had prolonged obviously, with failure patterns demonstrating the retrofit layers integrated to the original RC beams. The results show that high-temperature behavior of specimen can be improved obviously with the interface roughness grade Ⅱ and Ⅲ. It was also shown that when the levels of interface roughness are the same, high-temperature behavior of the strengthened beam drops rapidly as the increase of initial load.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2009年第4期102-107,共6页
Journal of Building Structures
基金
湖南省科技厅科技计划重点项目(06sk4057)
湖南省自然科学基金项目(20063137426)
关键词
钢筋混凝土梁
高性能复合砂浆钢丝网薄层
加固
高温试验
粗糙度
初始荷载
耐火极限
RC beams
high-performance ferrocement laminate （HPFL）
retrofit
high-temperature test
degree of roughness
initial load
fire resistance
