Study And Preparation Of Ecotype Porous Concrete Pavement Material

As an ecological road materials,Porous concrete material has certain permeability and sound absorption performance under certain load conditions due to its special mix proportion design and unique road construction technology.It has a positive effect on enhancing the drainage capacity of the pavement structure,alleviating the "heat island effect" of the city,reducing the noise of the road effectively and improving the surrounding environment,at the same time,it can also reduce the appearance of rainy water,glare and other phenomena,and improve the safety of vehicles traveling on rainy roads.Therefore,the study of porous concrete as pavement material is very important for engineering and ecological significance.In this paper,the following research is carried out on the design of porous concrete.(1)According to the packing theory and the void characteristics of porous concrete,the volume method is used to determine the mixture ratio parameters.(2)In order to explore the mechanical properties of porous concrete,experimental analysis is based on the structural characteristics of porous concrete and force characteristics.During this process,Using magnesite tailings instead of basalt lithotripsy as coarse aggregate for porous concrete pavement material,It not only meets the strength requirements,but also solves the environmental problems.(3)The linear relationship between the effective voidage and the total void ratio is obtained,the main factors affecting the permeability and sound absorption properties of porous concrete pavement materials are explored.At the same time,the correlation between the permeability coefficient and the effective void ratio is found and finally determine the best dosage.Through the above analysis,the basic ratio of porous concrete obtained as follows:cement:322.6kg/m~3?coarse aggregate:1653.26 kg/m~3?Chlorite iron tailings:165.3 kg/m~3?Fly ash:35.84 kg/m~3?Binder:11.37 kg/m~3?water:106.11 kg/m~3.Orthogonal experimental design method is used to optimize the results show that:When the aggregate grain gradation is(3~5)+(5~8)mm?water-binder ratio is 0.28?target porosity is 20%?The amount of additive is 6%,Its maximum compressive strength of the 28 days is 29.80 MPa,and the permeability coefficient can reach0.83mm/s.When the porosity is 25%and the thickness is 65 mm,the sound absorption performance of porous concrete pavement material is the best,and its noise reduction coefficient can reach 0.414.In this paper,a small amount of chlorite iron tail mineral powder and fly ash are added in the experiment,and the main effects are as follows:(1)Solve the problem of environmental pollution caused by the long-term stockpile of some solid waste.(2)Change the particle size distribution between the aggregate,reduce the porosity and improve the mechanical properties of porous concrete.(3)Effectively alleviating the appearance of freezing thawing cracking in winter,the test results show that:When the porosity is 20%,the amount of fly ash is 15%,the frost resistance of porous concrete is the best,and the loss rate of compressive strength is 12.4%.Finally,the construction technology of porous concrete pavement materials is briefly discussed,Three main links should be paid attention to in the process of construction,such as the preparatory work of the construction,the site construction and the maintenance after the molding and the later maintenance.