Study On Pavement Performance Of Recycled Permeable Concrete Reinforced With PVA And Basalt Fiber

In order to alleviate various problems caused by traditional cement pavement and reduce environmental pressure caused by construction waste,this paper applies recycled aggregate from broken waste concrete blocks to permeable concrete,and studies the possibility of applying recycled permeable concrete to light load roads.Due to the inferior physical properties of aggregates to natural aggregates,recycled permeable concrete has poorer road performance than ordinary permeable concrete.In order to promote the application range of recycled aggregates and improve the road performance of recycled permeable concrete,this article uses PVA(polyvinyl alcohol)solution and basalt fiber to enhance the recycled permeable concrete.The effects of different concentrations of PVA solution,recycled aggregate content,and basalt fiber content on the mechanical properties,permeability,and ductility of recycled permeable concrete were studied,and the reinforcement mechanism of PVA solution and basalt fiber was analyzed through microscopic images.Aiming at the fact that the physical properties of recycled aggregate are not as good as those of natural aggregate,the physical properties of recycled aggregate before and after treatment with PVA solution,such as apparent density,crushing value,water absorption,and moisture content,were tested.The results show that the improvement effect of PVA solution on the apparent density,water absorption,and moisture content of recycled aggregate is significant,but the improvement effect on crushing value is not significant.With the increase of PVA solution concentration,the improvement range of recycled aggregate performance gradually decreases.By testing the compressive strength,splitting tensile strength,permeability coefficient,and effective porosity of recycled permeable concrete,the effects of PVA solution and basalt fiber on the mechanical properties and permeability of recycled permeable concrete were analyzed,and the effects of two reinforcement materials on the ductility of recycled permeable concrete were studied through tensile compression ratio.The experimental results show that with the increase of recycled aggregate content,the mechanical strength of recycled permeable concrete gradually decreases,while PVA solution effectively improves the compressive strength of recycled permeable concrete,while basalt fiber has a more significant effect on improving the splitting tensile strength.However,PVA solution and basalt fibers have a negative impact on the water permeability of recycled permeable concrete,and with the increase of recycled aggregate content,the water permeability of recycled permeable concrete will also be correspondingly improved.Considering that recycled permeable concrete has a high water absorption rate and is more susceptible to water erosion,a water stability test of recycled permeable concrete was designed.The water stability of recycled permeable concrete reinforced with PVA solution and basalt fiber was studied using the compressive strength ratio before and after water saturation as an evaluation index for water stability.The research found that with the increase of recycled aggregate content,the water stability of recycled permeable concrete gradually decreases,and the improvement effect of PVA solution on the water stability of recycled permeable concrete is better than basalt fiber.A prediction model for the performance of recycled permeable concrete reinforced with PVA solution and basalt fiber was initially established.Comparing the fitting and measured results,it was found that the prediction model had a good degree of agreement.Through back scattering(BSE)microscopic images,the enhancement mechanism of PVA solution and basalt fiber on the performance of recycled permeable concrete was revealed from a microscopic perspective,and the feasibility of PVA solution and basalt fiber reinforcing recycled permeable concrete was analyzed.