Experimental Study On The Basic Properties Of Pervious Concrete

With the development of urbanization in China,the surface of urban is gradually covered by buildings and impermeable pavement,which has a negative impact on the ecological environment.Pervious concrete is an eco-friendly porous concrete,which has continuous pores compressive strengthen,and allows the water pass through its interior.Pervious pavement plays an active role in improving urban sound environment,light environment,thermal environment and so on.This paper mainly studies the basic properties of pervious concrete from the aspects of the workability,mechanical properties,water permeability and construction of pervious concrete.The quantitative study of the workability of the fresh pervious concrete is realized by the self designed test device and the evaluation method.When the β is between 4%to 12%,the pervious concrete is best.The influence of water cement ratio,the amount of silica fume,the type of admixture and the amount of admixture on the workability of the pervious concrete is studied.The idea of studying the workability of pervious concrete from the static yield stress and plastic viscosity of cement paste is put forward.The effects of water cement ratio,silica fume content,aggregate size,aggregate cement ratio,pigment content and sand ratio on the mechanical properties of pervious concrete are studied.The compressive strength of pervious concrete can reach 48Mpa,and the maximum flexural strength can reach 8Mpa.The pore structure characteristics of pervious concrete are analyzed by the two-dimensional slice of X-CT,and the compressive strength model of pervious concrete is put forward.The method of image analysis is used creatively to achieve the connected pores of pervious concrete,and the pore characteristics of connected pores are further obtained.The influence of water cement ratio,aggregate cement ratio,aggregate size and type of aggregate on pervious performance of permeable concrete was studied.The permeability coefficient of pervious concrete can be up to 8mm/s,and the permeability coefficient model of pervious concrete is analyzed and put forward.From the point of view of design and construction,the problems in the design and actual construction of pervious concrete pavement structure are analyzed,and their solutions are put forward.