Experimental Study On Flexural Performance Of Partially Prefabricated Lattice Steel Reinforced Concrete Beams

Steel reinforced concrete structures are mainly used in large-span structures,super high-rise buildings and large-scale industrial buildings,and have good earthquake resistance,durability and fire resistance.However,due to its complex structure,cumbersome on-site construction,and poor bonding performance between traditional solid web steel and concrete,its popularization and application are affected.To solve this problem,this paper proposes a new type of Partially Prefabricated Lattice Steel Reinforced Concrete Beam(referred to as PPLSRC beam).The PPLSRC beam adopts open-web section steel instead of solid-web section steel,which improves the problem of poor adhesion between traditional solid-web section steel and concrete,and enhances the integrity of the structure;part of the prefabricated part is cast-in-place in the production method and the ground is simplified The on-site construction process shortens the construction period.In order to provide experimental and theoretical support for the popularization and application of PPLSRC beams,this paper conducts an in-depth study on its flexural performance.The main research contents are as follows:(1)The bending performance test was carried out on 8 T-beam specimens of 4types,including 6 PPLSRC open-web steel-concrete beam specimens and 2 PPSSRC solid-web-type steel-concrete beam comparison specimens.Using ABAQUS finite element software,the influences of the parameters such as section steel type and precast plate thickness on the bending performance of PPLSRC beams are studied.The research results show that the open-web section steel can better improve the flexural bearing capacity of the specimen beam than the solid-web section steel,and the change in the thickness of the precast slab has less influence on its flexural performance;(2)Analyze the crack development,stress distribution,bearing capacity,load-deflection curve,etc.of the PPLSRC beam based on the results of the test and numerical simulation.The analysis results show that the PPLSRC beam has good mechanical performance,and its failure process is divided into three stages: no cracking,working with cracks,and failure.When the specimen is working with cracks,it can still maintain high bearing capacity and better Ductility(3)Compare the finite element simulation results with the test results from the aspects of failure form,stress cloud diagram,load-deflection curve,etc.The comparison results show that the error between the simulated value and the test value can be controlled within 8%,and the force state and failure mode of the model are similar to those of the actual test,so the created model has good applicability.The component attributes,interactions,load application methods and boundary conditions used in the modeling process are reasonable,and the force mechanism and failure mode of the specimen beam can be simulated more accurately;(4)Based on the existing codes,the calculation methods applicable to the stiffness,deflection and flexural capacity of PPLSRC beams are derived.By comparing the calculated value with the experimental value,it is found that the two are in good agreement.The calculation method in this article can be used to calculate the bending of the normal section of this type of beam.