Preparation,Properties Of Pervius Concrete Pavement Material

In the urbanization process the earth's surface of the city is hindered water material by building and concrete,etc hardened and covered progressively, These waterproof road surface brings the great negative effect to ecological environment of the city.The pervious concrete is a kind of environmental protection concrete, is one kind of concrete with continuous space made of special technology.There is certain intensity,have certain ventilate water permeability.Pervious concrete is a porous concrete paving material which permits rain and storm water runoff to percolate through it rather than flood surrounding areas or storm drains, enhance driving safety and comfort by preventing water spray,hydroplaning and decrease of skidding during rain, noise reduction and alleviate the effect of urban heat island.This paper discusses and studies preparation,mixture proportion design,strength,permeability and ecological protection, including improvement sound, thermal inUrban areas.In this paper, special mould is designed for pervious concrete; the suitable forming pressure is 3MPa through compareing with strength of forming by different pressure. The design of mixture proportion is on the basis of theory of filling and wraping.It studies the relations among of w/c ratio, porosity and strength, recommends the best range of w/c ratio 0.2～0.25, the goal porosity 15%～18%.And using smaller-sized aggregate, mineral mixture and polymer to enhance the strength of the pervious concrete. Have prepared the pervious concrete brick which accords with JC 446-2000 surface brick of concrete road on the basis of the above that studied, Compression strength is 32. 9MPa.Bending strength 4.5MPa. permeability coefficient is 5.7mm/s, freezing and thawing the strength of circulation to lose 12.5%. It designs and produces permeability coefficient tester completely in studying it sets up to be completely permeability coefficient and porosity the relational expressions of rate, offer the basis for design of the pervious concrete. On the basis of a series of temperature-reducing and noise-absorbing tests and researches, the paper discusses the environmental benefit of pervious concrete. The results may provide reference to the optical designing and wide application of pervious concrete. These two aspects are the new ideas of the paper. Study the change law of the surface temperature and evaporating intensity of different porosity concrete through the solar radiation function of simulation and natural ventilation condition. It can reach to cool range greatest 7.6℃.The results provide reference for the optimal porosity design of evaporation and cooling of pervious concrete pavement. Have set up the relation equation of porosity pervious concrete and its average sound absorption coefficient .This equation can evaluate the sound-absorbing ability of different porosity pervious concrete pavement.