Study On Preparation Of High Strength Pervious Concrete By Silica Fume,Fly Ash And Waste Rock Powder

Pervious concrete is a series of connected pores and concrete part of the skeleton of the structure of the porous structure of the porous concrete.This special structure allows the permeable concrete to collect and filter rain,weaken the noise,stabilize the temperature,improve the soil environment,ease the role of surface runoff.Over the years,waterlogging disasters seriously affected the normal life of the people of the city,and some even caused casualties and huge property losses,so the state proposed to build sponge city as soon as possible,pervious concrete is sponge city construction in the use of a wider range of materials.In this paper,the research on the preparation of high strength and permeable concrete with silica fume-fly ash-waste rock powder was carried out in view of the low strength of permeable concrete and the efficient utilization of waste rock and plastic building materials.The main research work and achievements of this paper are as follows:The effects of cement ratio,aggregate,water-reducing agent dosage,molding method and maintenance mode on the working performance of permeable concrete were studied by using cement,limestone aggregate,water reducing agent and water.The proportion of the reference mix,the water to take 0.23-0.26,the amount of water-reducing agent to take 1.8%,for the simulation site construction,molding method is used to hammer molding,forming a day with the mold into the conservation room maintenance,curing temperature 22?,Humidity 80%.Then,the effects of silica fume,fly ash and waste rock powder on the compressive strength and permeable coefficient of permeable concrete were studied.It was found that the compressive strength of pervious concrete increased first and then decreased from 0%to 8%When the fly ash content increased from 0%to 20%,the compressive strength and permeability coefficient of the permeable concrete decreased gradually when the fly ash content increased from 0%to 6%when the fly ash content increased from 6%The optimum dosage of waste rock is 10%,and the compressive strength and water permeability of the permeated concrete are reduced and the optimum dosage of waste rock powder is 10%when the content of waste rock powder increases from 0%to 20%.Finally,the compressive strength and the permeation coefficient were measured by three kinds of mixed materials of silica fume,fly ash and waste rock powder.The content of silica fume was 6%,the content of fly ash was 10%Stone powder content of 10%is the best.The mineral composition and microstructure of the composite cementitious materials were analyzed by XRD and SEM.It was found that Ca?OH?₂ was produced by waste rock powder and cement,which made the ash and fly ash play the effect of volcanic ash.Hydrated calcium silicate and other products to improve the microstructure of permeable concrete,making the microstructure is very dense.The study of this paper provides more options for the utilization of waste rock powder,providing more methods for the preparation of permeable concrete.