Study On Rainstorm Waterlogging Resistance Design And Water Purification Performance Of Novel Recycled Pervious Concrete

The processing and reuse of construction waste is an effective way to save resources and reduce environmental pollution,and it is a good way to use it in pervious concrete.Paving pervious concrete pavement is an effective way to reduce the probability of urban rainstorm waterlogging disaster.The novel pervious concrete with through hole has effectively improved many shortcomings of traditional pervious concrete,but the research on it has not been carried out at present.In this paper,a novel recycled pervious concrete with through-hole was prepared by using recycled coarse aggregate,and its basic properties were measured.According to the relationship between permeability coefficient,compressive strength with porosity,combined with the rainstorm grade(extra heavy rain,heavy rain and rainstorm),a novel recycled pervious concrete is designed to resist rainstorm waterlogging.Purification experiments of pollutants(COD,TP,TV,Cu)in rainstorm were carried out,and their purification mechanism was analyzed.(1)The novel recycled pervious concrete has good self-compaction,permeability coefficient and mechanical properties.The compressive strength and flexure strength can reach 93.3 MPa and 8.41 MPa.When the porosity is 0.95%,the permeability coefficient is 8.05 mm/s,achieving low porosity and high permeability coefficient.The SEM analysis shows that the hydration products improve the mechanical properties,which indicates that the novel recycled pervious concrete has good practical value.(2)Based on the relationship between the porosity and permeable coefficient and compressive strength of the quantitative relationship,determine the optimal porosity range of pervious concrete with different rainstorm resistance rate range,clear concrete strength grade,and the mechanics and rainstorm simulation test and analysis,it indicate that the compressive strength,flexural strength can meet the using demand of the pervious concrete pavement,excellent rainstorm waterlogging resistance.The design method of the novel recycled pervious concrete against rainstorm waterlogging provides a reliable basis for the design of the pervious concrete pavement in different regions(rainstorm grade).(3)The purification effect of novel recycled pervious concrete and its components on different pollutants was studied.The removal effect of block materials on different pollutants was generally lower than that of small granular materials.Under different pores,the increase of porosity provides more space for the adsorption of pollutants,and the removal rate increases accordingly.Through XRD and EDS analysis,hydration products of cementitious materials play a crucial role in the removal of pollutants.(4)Under the effect of different rainstorm,the novel recycled pervious concrete ranks the average removal rate of pollutants as follows:TP>Cu>TN>COD.As the rainstorm of ascension or precipitation speed increases,the removal rate of pollutants are decreased.As the rainstorm increases to the rainstorm,regenerated permeable concrete on COD,TP,TN,the average removal rate of Cu were reduced by 7.3%,6.6%,4.7%,9.0%,removal rate determines the pollutants and the contact time and the effect of adsorption material,so the faster the precipitation,to remove the worse effect.The new type of recycled pervious concrete has excellent performance and can be designed to resist rainstorm waterlogging according to the rainstorm grade.Therefore,it is feasible to apply the novel recycled pervious concrete to the construction of sponge city.