Study On Fire Resistance Of Beam-Beam Joints Based On Profile Steel In Prefabricated Reinforced Concrete Structures

At present,China's construction field is gradually developing towards the direction of industrialization.Prefabricated assembly building is an important carrier for the diversified development of industrial buildings.The development of prefabricated buildings can effectively control budget costs,construction duration,improve quality,and improve the safety of on-site construction,the coefficient reduces the generation of waste and the waste of energy to achieve the sustainable development of the building.The research of prefabricated steel reinforced concrete beam-beam joints is mostly focused on the research at normal temperature.No report on the fire resistance of prefabricated steel reinforced concrete beam-beam joints at high temperatures has been reported.Therefore,it is necessary to study its fire resistance.This thesis presents a new beam-beam joints based on profile steel in prefabricated reinforced concrete structures.Connect two simply supported reinforced concrete beams through this node.Composition of fabricated steel concrete beam.And research on this fabricated steel concrete beam.Numerical simulation method is used to analyze the mechanical properties of fabricated steel concrete beams under fire.The main research work is as follows:(1)Based on the research and analysis of thermal parameters and mechanical properties of concrete and steel under high temperature at home and abroad,the model of the concrete and the thermodynamic parameters and the thermodynamic constitutive relation in the simulation are selected.(1)Connect two simply supported reinforced concrete beams through this node.Forms assembled steel concrete beams.(2)Using finite element software ABAQUS to establish three-dimensional temperature field calculation model of fabricated steel concrete beam,calculation model of bending capacity at normal temperature and theoretical calculation model of fire resistance at high temperature.(3)Using ABAQUS thermo-mechanical coupling model for fabricated steel concrete beam and simply supported reinforced concrete beams of the same size at high temperature is compared.It is known that the fabricated steel concrete beam is much better than simply supported reinforced concrete beams of the same size,and analysis of stress changes of concrete,steel and bolts in fabricated steel concrete beams at high temperatures.(4)Comparative analysis of parameters affecting the fire resistance of fabricated steel concrete beams.Research shows: the increase in bolt strength does not significantly improve the fire resistance limit of the component;the increase in bolt diameter improves the fire resistance limit of the component;the increase in the thickness of the steel plate significantly improves the fire resistance limit of the component;the smaller the load ratio,the higher the fire resistance limit of the component.The research in this paper can provide reference for the fire resistance design of fabricated steel concrete beams.