预应力CFRP布加固负载混凝土梁受剪性能试验

Experimental research of shear resistance performance on loaded concrete beam reinforced with prestressed CFRP sheet in diagonal section

摘要:

为研究负载状态下利用预应力碳纤维布加固混凝土梁斜截面受剪性能,根据配箍率的不同制作3组共计12根钢筋混凝土梁,每组选择1根混凝土梁进行单点加载受剪试验,获取极限受剪承载力及裂缝分布等试验数据.对另9根梁预加载至极限受剪承载力的0.4倍,在持荷状态下对试验梁弯剪区段利用预应力碳纤维布加固.完成这9根梁负载加固后的斜截面二次受力受剪承载力试验,在试验数据基础上分析负载加固梁斜截面受剪破坏机理和影响因素.结果表明:采用预应力碳纤维布加固负载混凝土梁斜截面能够抑制斜截面裂缝的产生和发展,增大混凝土受压区高度,提高斜截面受剪承载力.

Abstract:

To study the shear 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 ratio of reinforcements. In each group, one beam has been chosen to take as contrast beam for single point loading to get experimental data on bearing capacity, as well as fracture distribution. Before the tests, as much as 0.4 times of ultimate shear bearing capacity to the other 9 beams was applied, then the test beams were strengthened at the shear section with prestressed CFRP sheet under load before. Based on the test data, the shear failure mechanism and effect factors of the beams were analyzed. The test result shows that the prestressed CFRP sheets at inclined section could restrain the generation and development of cracks, increase the height of the compression concrete in compression-shear area, as well as improve the shear bearing capacity of inclinded section.