Study On Stress-strain Relationship Of CFRP-confined Injury R.C Columns

FRP-confined concrete columns have a bright prospect in the form of reinforcement with its deformation confined concrete good performance and construction convenience etc,and have good reinforcement effect of economical characteristic.Therefore,CFRP cloth constraint different damage concrete columns,the research on the relationship between stress strain has become an urgent need to solve scientific questions.In this article,12 injured RC columns were strengthened by CFRP sheets to study the stress-strain relationship under axially loaded compression,the main research contents are as follows:Consider 6 damage degree,2 kinds of CFRP reinforcement fabric quantity of 12 CFRP constraint different damage concrete columns and contrast the column for the axial compression tests,and the load on the state of the degree of damage with different concrete columns using different quantities of CFRP constraints failure characteristics.The test results show that:by CFRP C30 constraints different damage concrete columns compression test results regardless of three way 50 mm wide space 125 mm(effective winding cloth and concrete surface area CFRP ratio,0.3)or 50 mm wide space 50 mm(effective winding cloth and concrete surface area CFRP ratio,0.5)can effectively improve reinforced concrete structures in ultimate bearing capacity,its ductility also get strengthened;The load reinforcement state,damage degree of CFRP cloth constraints have obvious influence on the effect;The same damage degree,with the increased amount of CFRP reinforced cloth,the damage of reinforced concrete columns compressive capacity and ductility will increase;CFRP reinforcement fabric quantity the same situation,with the increase of concrete component damage degree,component limit bearing capacity is reduced,and in the degree of damage is about 0.6 limit bearing capacity of the lower speed,its reason is the degree of damage in 0.6 degree about component appeared crack,strain to lag.In the damage degree is 0?0.7,the ultimate bearing capacity of reinforced columns with increased and the degree of damage decreased;In addition,the same damage degree,the greater the amount of CFRP reinforcement,the greater the ultimate bearing capacity of the column.Finally,based on the test result,suggest the strip CFRP constraint no damage concrete columns peak stress formula,agree well with the experimental data;Put forward the damage degree of CFRP constraint concrete structures in the influence of the peak stress formula,the calculation results agree well with the experimental data;Through to the CFRP constraint damage stress-strain relationship of concrete analysis and study of the CFRP belt are bound damage concrete columns stress-strain relationship curve model,and the test results.