Experimental Study On Shear Resistance Of Hollow Steel Concrete Composite Beams

With the rapid development of China’s economy,the construction industry’s demand for high-rise buildings is increasing,so the construction market urgently needs steel-concrete structural materials with excellent shear performance.The fasting steel-concrete structure has also been widely recognized by the construction market because of its good shear resistance,and has been favored by many research institutions as well as construction institutions.From the point of view of market economy,the fasting steel-concrete structure needs less steel but lower cost than the traditional concrete structure,so the fasting steel-concrete structure can reduce the cost of civil construction and is very suitable for large-scale popularization and application.In this paper,the shear performance of fasting steel-concrete composite beams is analyzed,and 6 steel-concrete composite beams 4 of which are fasting steel-concrete composite beams and2 ordinary concrete beams are used for experimental analysis.At the same time,the finite element method is used to analyze the shear condition of steel-concrete composite beams,and the selected unit types,constitutive relations of the constituent materials,the construction of geometric models and the division of grids are reasonably selected and set in the finite element model.In order to effectively analyze the influence of various parameters on the shear resistance of fasting steel-concrete composite beams,the rationality and validity of the relevant parameters are determined by multiple trial calculation,the actual dimensions and mechanical parameters of the steel skeleton members of the beam are matched,and the CAE model is finally established.A monotonically incremental concentrated load is set to load the model beam at two points,thus calculating the ultimate tensile strength of the steel-concrete,and the following conclusions are finally drawn according to the test and the finite element calculation results:SRCL series of fasting steel-concrete composite beams whether bending cracks or oblique cracks,its cracking time and development trend are later than or slowdown in the RCL series of ordinary reinforced concrete beams;However,the development of cracks in the SRCL-01 and 02 beams of angle steel limbs is relatively slow in the relative arrangement of SRCL-03 and 04 of the dorsal angles of the limb.Because of the high stiffness of the fasting steel-concrete skeleton itself,the former limits the overall deformation of the beam,and the strain of the concrete itself under the same load is much smaller than that of the beam arranged in the steel cage,so its cracking time is delayed.The latter because of the angle steel arrangement form causes the vertical plate to be arranged relatively by the beam center,its two sides of the concrete protective layer thickness is large,the abdominal concrete cracking,the vertical plate is relatively late to participate in the force.The steel material in the fasting steel-concrete has a strong restraint effect on the whole concrete.It can effectively hinder the development of the oblique cracks in the concrete,and improve the compressive capacity of the concrete to a great extent,so it can improve the shear bearing ability of the fasting concrete beam,which is obviously impossible for ordinary concrete beams,Therefore,the fasting steel-concrete composite beam can improve the shear bearing capacity of the beam to a great extent.In addition,because the constraints of concrete are affected,although the concrete is crushed,but the concrete can still play a better carrying role,so can change the shear failure of the beam to produce brittle damage,can significantly enhance its ductility,Therefore,it can be concluded that the fasting steel-concrete composite beam can produce good shear resistance and ductility in the oblique section failure.The method of spring unit is adopted to simulate the slip between steel beam and concrete slab,and the pressure test of beam element in concrete slab is carried out,so that the reasonable slip of laminated surface can be tested,and the strength of the bolt on the concrete slab can be reflected,and the longitudinal shear resistance of the combined beam can be better tested.In addition,combined with the introduction of the rigid concrete composite beam above,the use of transverse steel bars can minimize the longitudinal cracking of the concrete slab caused by the bolt,so that the composite beam plays the maximum flexural bearing capacity.Therefore,by comparing and analyzing the shear resistance of fasting steel-concrete composite beams and the shear of ordinary concrete beams,it is better to apply the fasting steel-concrete composite beam to the engineering field,so as to play a certain supporting role in improving the quality of the project.