摘要
为研究负载状态下利用预应力CFRP布加固混凝土梁力学性能,根据截面配筋率的不同,设计制作3组共计12根钢筋混凝土简支梁,每一组选择1根作为普通钢筋混凝土对比梁,其余3根预先加载至对比梁正截面受弯承载力的40%,在持荷状态下利用预应力CFRP布对梁底混凝土进行加固。完成12根试验梁两点加载受弯试验,获得承载力、变形及裂缝分布等试验数据;利用有限元软件ABAQUS建立12根试验梁的有限元分析模型,且在每组模型中建立一根普通CFRP布加固负载混凝土梁的分析模型,完成预应力CFRP布加固负载混凝土梁力学性能的分析。试验及分析结果表明:CFRP布的张拉与粘贴对持荷状态下梁的既有裂缝和变形没有明显影响,预应力CFRP布粘贴加固后试验梁二次受力过程中,预应力CFRP布较好的参与至梁的受力过程,发挥CFRP强度高的特点,明显提高构件正截面受弯承载力,延缓裂缝的发展,抑制构件的变形。基于试验与分析数据,建立预应力CFRP布加固负载混凝土梁正截面受弯承载力计算公式和截面刚度计算公式,计算结果与试验结果吻合较好。
In order to study mechanical performance of RC beams strengthened with prestressed CFRP sheets under load,three groups of reinforced concrete beams,total of 12,have been made according to the reinforcement ratio. In each group,one beam has been chosen to take as contrast reinforced concrete beam,the other beams preload to the ultimate flexural bearing capacity by 40% of contrast beams,then the test beams are strengthened on the bottom with prestressed CFRP sheet under load. The twelve test beams with two-point loading was completed and the test data such as the bearing capacity,deformation and crack distribution were obtained; founded the finite element modes of twelve test beams by using finite element software ABAQUS,and in each group has established one analysis model of RC beams strengthened with CFRP sheets under load,completed the mechanical performance of RC beams strengthened with prestressed CFRP sheets under load analysis. Test and analysis results indicate that there is no obvious influence for the existing cracks and deformation by using CFRP sheet tension and paste under load,in the process of secondary load,prestressed CFRP sheets can participate in force betterly,making effectively use of high strength of CFRP sheets,improving the flexural capacity obviously,delaying the development of crack,restraining the deformation. Based on the test and analysis data,the calculation formula of flexural bearing capacity and section stiffness of RC beams strengthened with prestressed CFRP sheets under load is established,The calculated result is better coincided with the test result.
出处
《土木工程学报》
EI
CSCD
北大核心
2013年第S1期319-328,共10页
China Civil Engineering Journal
基金
国家自然科学基金重大研究计划"重大工程的动力灾变"培育项目(90915003)
中央高校基本科研专项基金(DL09CB04)
