Experimental Study On Flexural Behavior Of Composite Reinforced Concrete With Short Fiber And Textile

As a new type of building material,fiber reinforced concrete is widely used in construction engineering.At present,the main type of fiber reinforced concrete is short fiber,However,the misalignment of short fibers distributed in concrete has a low utilization rate and has limited reinforcing effect on concrete.The fiber fabric is a continuous fiber-reinforced material with a fixed warp and weft direction,and the reinforcing efficiency of concrete is much higher than that of short fiber.If only a single fiber is incorporated,only a certain level of performance of the concrete can be improved.In this paper,short fibers and fabrics are used simultaneously to reinforce and toughen the concrete at various levels,the performance of the concrete can be improved as a whole.The bending properties of composite reinforced concrete with short fiber PVA and glass fiber grating fabric were studied by field test and finite element simulation.The main research contents and achievements are as follows.(1)Inorder to investigate the influence of concrete matrix strength,critical textile ratio and surface treatment methods of fiber grid on the flexural properties of cement concrete,ten groups of square concrete plates with dimensions were tested through bending experiment.The research result shows that When the other conditions remain unchanged,the ultimate load of the concrete square slab increases with the increase of the strength of the matrix concrete;at the same time,the overall flexural performance of the fiber grid reinforced concrete square slab strengthens as the distribution ratio increases;The surface brushed epoxy resin and the viscous sand treatment can effectively improve the overall performance of the fiber bundle and increase the ultimate load of the cement concrete.(2)Inorder to investigate the flexural properties of PVA fiber and fiber grating composite reinforced concrete,the variables such as PVA content,grid surface treatment method and distribution ratio were changed,and the influence of these factors on the bending performance of concrete was studied.The research result shows that: When other conditions remain unchanged,increasing the distribution rate can effectively improve the ultimate load and energy absorption capacity of the specimen;the fly ash and sticky sand on the grid surface can increase the ultimate load,limit deflection and energy absorption of the specimen.But the surface of the grille sticky fly ash to enhance the effect is better;the matrix after adding PVA,can significantly improve the bending properties of the matrix and the energy absorption capacity,and in the condition of preset volume dosage,the bending performance of specimen increases with the increase of PVA content.(3)The finite element analysis of the short fiber and fabric composite reinforced concrete test was carried out by ANSYS.The simulated load deflection curve is compared with the experimental data,The results showed that the model selection is reasonable.The curves obtained from the numerical simulation of each set of test pieces are in good agreement with the curves obtained from the test in the elastic phase and the overall trend is similar.The numerical simulation results and test results of the test specimens in terms of the ultimate load of each set of specimens compared with a certain error,the error range is between 2.1% and 28.1%.In the limit deflection of each group of specimens,except for a few specimens,the ultimate deflection of the other specimens is greater than the test value,the error range Between 8.8% and 35.5%.The numerical simulation method is feasible as a whole,but some details still need further improvement.