Experimental Study On Basic Mechanical Properties Of PVA Fiber Waste Ceramic Recycled Aggregate Permeable Concrete

Pervious concrete plays an important role in the construction of “sponge city” and ecological environment protection.It can not only timely evacuate rainwater to improve driving safety,but also timely supplement urban groundwater to maintain urban ecological balance.On the other hand,China is a big country in ceramic production.Every year,a large amount of waste ceramics is produced.If waste ceramics is used as recycled aggregates,the burden on the environment can be reduced.The waste ceramic aggregates have glaze effects on cement mortar and The bond strength and physical properties are lower than the traditional aggregate factors,and the porous characteristics of the permeable concrete itself lead to the low strength of the permeable concrete of the waste ceramic recycled aggregate.In this experiment,the optimal mix ratio is obtained by orthogonal experiment method.Performance optimization studies and analysis,the conclusions are as follows:(1)When preparing PVA fiber waste ceramic aggregate permeable concrete,the feeding mode is selected multiple times,the forming process is selected by manual insertion molding,the standard curing method is selected during curing,and the target volume ratio is controlled by the test mixture ratio control method.(2)Selecting the four factors of target porosity,water-cement ratio,waste ceramic recycled aggregate replacement rate and PVA volume content for orthogonal test,each factor includes three levels,through compressive strength,flexural strength,The actual porosity and water permeability,the worst case analysis found that the main factors affecting compressive strength,flexural strength and water permeability are the target porosity.(3)Comprehensively consider various factors to determine the best test mix ratio,and obtain the best mix ratio of target porosity 20%,water-cement ratio 0.32,waste ceramic substitution rate 30% and PVA volume content 0.15%.The test specimens were prepared with 28 d compressive strength of 22.8MPa,28 flexural strength of2.98 MPa and permeability coefficient of 5.41mm/s.(4)The silane coupling agent was treated with 1% concentration of wasteceramic aggregate,6% silica ash was mixed with 1% concentration of silane coupling agent to optimize the performance of PVA fiber waste ceramic recycled aggregate permeable concrete.The strength of the test piece after the interface agent treatment increased the compressive strength and the flexural strength by 18.7% and 15.1%respectively.The compressive strength and resistance of the test piece incorporating the silica fume were formed.The flexural strength increased by 27.1% and 24.83%,respectively.When the incorporation of silica fume and interfacial treatment work together,the strengthening effect is optimal,the flexural strength is increased by 33.6%,the compressive strength is increased by 43.6%,and the water permeability and actual porosity are improved.The rate change is small,and the solution is the best solution for performance optimization.