| Reasonable allocation of HRB600 steel bars in concrete structures can effectively reduce the cross-section size of components,increase the building area,save material consumption,and reduce resource and energy consumption.It is in line with the concept of green building,energy saving and emission reduction advocated by the Chinese government,and is in line with sustainable development strategy.The experimental study and theoretical analysis of the axial and eccentric compression performance of the HRB600reinforced concrete column can provide a basis for further revision of relevant industry specifications and promote the application of HRB600 steel in engineering.In this paper,six HRB600 steel bars,one HRB500 reinforced concrete short column and two plain concrete short columns were subjected to axial compression test to analyze the influence of different design parameters on the axial compression performance of reinforced concrete columns.The test results show that the peak strain of the axial compression short columns decreases with the increase of the strength of the concrete and increases with the increase of the strength of the steel bar and the hoop ratio.The slenderness ratio has little effect on the peak strain.The design value of the compressive strength of the HRB600 steel is 450MPa.The bearing capacity of the axial compression can be calculated according to the pressure bearing capacity formula specified in the Code for Concrete Structure Design(GB50010-2010),and has sufficient safety reserve.The eccentric compression tests were carried out on six HRB600 reinforced concrete columns,and the influence of different eccentricity and reinforcement ratio on the stress and deformation performance of reinforced concrete bias columns was analyzed.The test results show that HRB600 reinforced concrete bias test pieces are damaged by concrete crushing on the compression side.The eccentricity has a great influence on the lateral deflection of the test column,steel strain and concrete strain.The greater the reinforcement ratio,the smaller the lateral deflection of the test column,and reinforcement ratio has little effect on steel strain and concrete compressive strain.The bending moment increase coefficient and compression bearing capacity of HRB600 reinforced concrete bias test piece can still be calculated according to the corresponding formula of the Code for Concrete Structure Design(GB50010-2010).Take HRB600 steel bar f_y=520MPa,f_y’=480MPa to calculate the bearing capacity of the eccentric compression column with sufficient safety reserve.The reliability index of axial compressive capacity of high-strength reinforced concrete columns was calculated by MATLAB programming,and the influences of different steel strength,concrete strength and reinforcement ratio on the reliability index of concrete axial columns were analyzed.The research results show that the average value of the reliability index of the test component of the research group is 4.4.The larger the uncertainty coefficient of the calculation mode,the larger the reliability index.The reliability index of the high-strength steel test piece increases with the increase of load effect ratio,and it shows a trend of increasing first and then decreasing.The reliability index of high-strength steel specimens increases with the increase of the strength grade of steel and concrete,and decreases with the increase of the reinforcement ratio.The high reinforcement ratio is unfavorable to the structural members. |
