| As the country advocates sustainable and green development,the country has vigorously promoted natural gas to replace coal in human daily life.With the continuous research on natural gas and the continuous development of gas industry in cities,gas supply pipelines are increasingly popular in residential buildings,but related gas accidents are also increasing.Such accidents caused by gas will not only bring people economic losses and building collapse,but also cause personal injury.Many scholars and researchers have conducted a series of studies on gas explosion in confined space,mainly focusing on the factors that affect gas explosion and the hazards of gas explosion.Since our country started late for the use of natural gas,so the research in this respect is late compared with foreign countries,there are few researches on the concrete components under the action of gas explosion.Gas explosion is different from solid explosive explosion,gas explosion pressure rise slowly,lasting a long time.There are many researches on RC plate under solid explosive,but few researches on the antiknock performance of RC plate under gas explosion.On the basis of existing reinforcement,both carbon fiber cloth and carbon fiber reinforcement can play a good strengthening effect on concrete slabs,so carbon fiber cloth and carbon fiber reinforcement together can play a better strengthening effect on concrete slabs.Therefore,this paper mainly studies the antiknock performance of reinforced concrete slabs reinforced by carbon fiber composite under indoor gas explosion.The main research contents include the following aspects:1.FLACS software was used to establish a closed detonation chamber with a blowout port for simulation.The simulation results were compared with the experimental results to determine the relevant parameters and verify the correctness of the numerical model.Combined with the actual situation,a typical kitchen model is established,and corresponding points are selected on the floor to get the overpressure time history curve of gas explosion load.2.For the reinforced concrete plate and carbon fiber composite reinforced plate model,the reinforcement,concrete and carbon fiber materials are separately modeled,and various materials are combined through coupling and common node methods.The overpressure time history curve of gas load is loaded on reinforced concrete slab and carbon fiber composite reinforced concrete slab,and the antiknock performance of ordinary reinforced concrete slab and carbon fiber composite reinforced concrete slab under indoor gas load is studied.The Mises stress of concrete,the maximum principal stress of concrete,the maximum displacement of concrete slab,the equivalent stress of carbon fiber cloth and the first principal stress were compared and analyzed.The research results show that the role of carbon fiber materials is mainly in the late stage of indoor gas load,carbon fiber can curb the expansion of cracks on the reinforced concrete plate,so as to improve the integrity of the carbon fiber composite reinforced plate,improve the bending stiffness of the plate,and finally the carbon fiber composite reinforced plate bending failure mode.3.The parameters of influencing factors on the antiknock performance of reinforced concrete slabs with carbon fiber composite reinforcement were analyzed,including the method of carbon fiber composite reinforcement,carbon fiber thickness,carbon fiber diameter,etc.The analysis shows that the different reinforcement methods have a certain influence on the antiknock performance of reinforced concrete slabs.Among the 6 different carbon fiber composite reinforcement methods,Z-CZ-JG type(carbon fiber cloth pasted in the middle and carbon fiber reinforcement plates embedded in the zigzag type)reinforcement methods have the minimum plate center displacement and the best reinforcement effect under the action of gas.4.When the reinforcement mode is determined as Z-CZ-JG type and other conditions remain unchanged,the maximum displacement of reinforced concrete slab gradually decreases with the increase of the number of layers of carbon fiber cloth.However,the delay effect is weakened when the number of layers is 2 or above.When the reinforcement mode is determined as Z-CZ-JG type and other conditions remain unchanged,the maximum displacement of concrete slab gradually decreases with the increase of the diameter of carbon fiber reinforcement.Increasing the diameter of carbon fiber reinforcement can improve the anti-knock performance of the slab.When the reinforcement mode is determined as Z-CZ-JG type and other conditions remain unchanged,reducing the space between carbon fiber bars can improve the anti-knock effect of the plate,but the improvement effect is not obvious. |
