Study On Preparation And Performance Test Of Manufactured Sand Pervious Concrete

The pervious concrete is a kind of ecotype building material with a very bright developing prospect,it can improving groundwater resource,permits rain and storm water runoff to percolate through relieve water logging and city flood,and alleviate the effect of urban heat island,it will play an important role in urban ecological city construction.In consideration of the development of pervious concrete application technology is unbalanced,and the differences in raw materials between different areas.A preliminary study on pervious concrete have done in this paper,including mixture proportion design,strength,permeability preparation,durability and production and construction.It provides a theoretical reference for the production of pervious concrete using local raw materials,promoting the development and application of pervious concrete in the region,and "sponge city" construction.Firstly,the specific surface area of aggregate is calculated based on the residual sieve of aggregate,and put forward the mix ratio design of concrete by reasonable selection paste thickness and water-binder ratio,and verify its feasibility and rationality in technology.The influence of key factors such as aggregate size gradation,water-binder ratio,bone-binder ratio,sand ratio and mineral admixture on the strength and permeability of pervious concrete is also studied.The results show that:(1)Aggregate particle size should be chosen according to the strength and permeability of pervious concrete;(2)Water-binder ratio affects the fluidity of cement slurry,pervious concrete has better strength and permeability when W/B=0.28~0.32;(3)Bone-cement ratio affects the state of aggregate wrapped by cement slurry,pervious concrete has better strength and permeability when G/B=3.2~3.4;(4)Compressive strength can be improved by mixing appropriate amount of manufactured sand,recommended ratio of sand is 9%;(5)The comprehensive performance of pervious concrete can be improved by adding 15% slag powder.Secondly,the flexural strength,wear resistance and frost resistance of pervious concrete are studied preliminarily in this paper.The results show that the pervious concrete has lower flexural strength,the flexural strength can be improved to a certain extent by mixing appropriate amount of manufactured sand;The abrasion resistance and frost resistance of pervious concrete have good performance,the wear resistance of pervious concrete increases with the increase of slurry content;The moderate sand can improve the frost resistance of pervious concrete,especially 9% sand ratio.Finally,the mixing and forming technology of pervious concrete are tested,a mixing process of pre-wetting aggregate is put forward,and adopt covering and watering curing method.The production and construction process and quality control are analyzed and summarized,combined with the application of pervious concrete pavement engineering.