Experimental Research And Mix Proportion Design Of Porous Concrete Based On Orthogonal Test Method

Porous concrete material can be widely used in city light traffic roads, parks, squares, parking lots, sidewalks, sports, underground construction, green areas, water purification, sound-absorbing materials and so on. It also has broad application prospects in the field of rail transportation porous concrete, such as for addressing urban tram drainage problems."Sponge city" has become the high-frequency keyword in the country’s urban development plans, the importance of the development of "Sponge city" is self-evident. However, the research and application of porous concrete is still in its infancy in China. Under this background, porous concrete as a necessary functional material have a very important and realistic significance for constructing and developing the "sponges City". In order to effectively promote the popularization and application of porous concrete in our country, the paper based on orthogonal test method carried out a lot of work about porous concrete complex design and experimental studies. The main contents and conclusions of the paper are as follows:(1)The mix proportion calculation analysis of porous concrete:compare different mix proportion design; give the example of the base mix proportion design about porous concrete by using the volume method.(2)Design the test mix proportion of porous concrete by orthogonal test method:select orthogonal design table with three levels and seven factors, and the last one set to the empty column. Consider the six factors:target porosity, water-cement ratio, aggregate type, silica fume and fly ash, respectively, with three levels changing.(3)Compressive strength, porosity pervious concrete were measured, and the permeability coefficient was measured by using self-designed device.(4)Research on the method to improve the strength of porous concrete in case of meeting the permeable capability, and discuss the impact of sand ratio and molding method to porous concrete.(5)Research on the relationship between porosity and permeability coefficient, porosity and compressive strength, permeability coefficient and compressive strength with fitting relationship given, and a multiple linear regression analysis of each test factor for compressive strength and permeability coefficient was given.(6)In this paper, the final parameter values of porous concrete:target porosity takes 16%, water-cement ratio take 0.32, the aggregate type takes B, silica fume takes 5%, fly ash takes 10%, stirring way takes the third, sand ratio takes 6%, molding pressure 5MPa and continuous 90s. In such a parameter value, the porous concrete compressive strength reached more than 30MPa, permeability coefficient 1.24 mm/s, priced at 276 yuan per cubic meter.