Experimental Study On Pervious Concrete Pavement Of Cement-based Composite Materials

With the development of economy and urbanization in China,the urban surface is covered by reinforced concrete structures and pavement.These materials affect the water circulation of soil and air,which is bad of the ecological environment.Pervious concrete is a new kind of pavement material with green ecology and permeability function.Pervious concrete pavement is conducive to improve urban water circulation environment and alleviating heat island effect.In view of the climate characteristics of the cold regions in the north of China,in order to improve the strength and water permeability of pervious concrete pavement,admixture I was developed and compared with three kinds of similar additives sold on the market.Orthogonal test was designed from three factors: target porosity,water-binder ratio and aggregate particle size distribution,and its influence on mechanical properties and permeability of permeable concrete was analyzed.The effects of porosity,water-binder ratio,aggregate particle size distribution,aggregate particle size and forming method on permeability coefficient of pervious concrete were studied.The effects of admixtures,porosity,water-binder ratio,aggregate particle size distribution,aggregate particle size and forming methods on the mechanical properties of pervious concrete were studied.The reasons for the effects of internal structure of pervious concrete sample,size and distribution of internal structure pore on the mechanical properties of pervious concrete were analyzed.In this paper,the internal pore distribution of pervious concrete is characterized by a simple and easy-to-operate slice rubbing method.The size and number of different internal pore is measured to characterize the internal pore structure characteristics are obtained.Further experimental study on corrosion resistance,frost resistance and abrasion resistance is carried out.The results show that the durability of pervious concrete with self-developed admixture I meets or surpasses the requirements of specifications and is suitable for area of north of China.The self-developed admixture I can significantly increase the strength of pervious concrete pavement compared with three kinds of market pervious concrete pavement admixtures.The compressive strength,permeability coefficient,sulfate corrosion resistance and frost resistance of pervious concrete reach 32.3MPa,2.31mm/s,KS30 and D25.The results show that porosity is the main factor affecting the strength and permeability of pervious concrete pavement,followed by water-cement ratio,and aggregate size has a more significant impact on compressive strength and permeability coefficient than aggregate gradation.