Performance Study Of Lightweight Aggregate Concrete Compression Member Reinforced With HRB500 Steel Bar

Lightweight aggregate concrete(LWAC)structure has many excellent characters such as lightweight,heat preservation,fire-resistant,anti-seismic and so on.Compared with the abroad,the strength of steel bars in LWAC structure are low,which may cause many problems such as the intensive use of steels in structure,the difficulty of construction and the large use of steel.By the same time,this will cause the high energy and resourceconsumption and run counter to “ the sustainable development policy” our government advocates.In this paper,according to the experiment of 9 LWAC axially compressed columns with HRB500 steel bars and 1 with HRB400 steel bars,9 LWAC eccentrically compressed columns with HRB500 steel bars and 1 with HRB400 steel bars,observe the failure mode of samples,analyze the factors of affecting bearing capacity,put forward formulas of LWAC columns with HRB500 steel bars under axially and eccentrically loaded,provide proposed formula of second order effect about LWAC eccentrically loaded columns,by using the ABAQUS to simulate the bearing capacity of axially loaded and eccentrically loaded components and analyzing the influencerule of every designparameters for the bearing capacity.The main contentsare as follows:1.With the increase of LWAC strength,longitudinal reinforcement ratio,stirrup ratio and the decrease of slenderness ratios,the bearing capacity of axially components increase,however,the stirrup ratio has limited effect for the ultimate bearing capacity.According to the analysis of the LWAC peak strain,oldregulation still be suggested.The bearing capacity of axially compressed components was calculated by Chinese existing code,the ratio of test value and calculatedvalue is 1.05,which indicates that calculated formula is in a certain security,the bearing capacity can still use the formula put forward by this paper..2.The mechanical properties of LWAC eccentrically loaded columns with HRB500 steel bars are in accordance with common concrete eccentrically loaded columns with steel bars through the contrastanalysis of the data.The planecross-sectionassumption of mid-span LWAC is still satisfied in each stage load.The ratio of test value and bearing capacity calculated according to Chinese existing code is 1.157,which indicates that calculated formula is in a certain security.3.The second order effect formula of LWAC eccentrically loaded components with HRB500 steel bars is derived by the approximate deflectionmethod and the expand eccentricity method.Through comparing with the test value,it shows that:The second order effect formula derived by the approximate deflectionmethod is the same as the formula used in common concrete,by using this formula,the calculated value is closed to the test value and in a certain security.The formula derived by the expand eccentricity method can show the difference between common concrete and LWAC,however,it needs complicated calculation and is too safe for Large eccentric compression members.4.On the basis of experiment,establish models of axially compressed component and eccentrically compressed component by ABAQUS,through the nonlinear calculation and compare with the experimental results.The research shows:The failure mode of axially compressed component model and eccentrically compressed component model are the same as experimental results.The final calculated ultimatebearingcapacity is matched the test results.ABAQUS can response the mechanicalcharacteristics of LWAC columns with HRB500 steel bars well and the influencerule of every designparameters for the bearing capacity.