Study On Bond Slip Of Lightweight Steel And Foam Concrete Composite Structure

Steel reinforced concrete composite structure is a new structural system composed of steel and concrete.The composite structure gives full play to the excellent properties of steel and concrete,and it has the advantages of better material utilization,good seismic performance and convenient construction.However,the domestic and foreign research on steel reinforced foam concrete composite structure is still at the initial stage.In this paper,the experimental study of steel and concrete is carried out according to the bonding test between steel and concrete at home and abroad.First of all,through the study of the previous study of bond slip test,this paper selected the push-out test as the subject of experimental research.In this paper,a total of 40 specimens were designed for the interface mechanical properties of C-shaped steel foam composite components.The effects of three factors,such as density,hole spacing and the number of transverse ribs,on the bond slip performance of C-shaped foamed concrete were investigated.Through the observation of the specimen in the test,the interface failure modes of each specimen are summarized.Then,through the processing and segment fitting of the measured data,the bond and slip constitutive relation between the C-shaped steel and the foamed concrete is obtained.Meanwhile,we get three sets of data of characteristic value load for every sample,which including initial slip bond strength,limitation jointing strength,and remnant jointing strength.Based on the data above,the author drew the variation curve of characteristic value strength changes with different segments with Excel.Then matched these curves and obtained the relation equation between characteristic values and impacted segments.And then the error analysis of the obtained relational equation is considered to be consistent with the experimental data.Finally,the numerical simulation is carried out by finite element software.The finite element modeling and calculation method of C-shaped steel and foam concrete are analyzed.In order to comprehensively consider the interaction between C-shaped steel and foam concrete,three non-linear spring units are used to simulate the mutual relationship between C-shaped steel and foam concrete in three directions(normal,transverse tangential and longitudinal tangential)effect.Finally,the simulation results are compared with the experimental results,and the results show that the two models are in good agreement,and the accuracy of the model is verified.