Research On The Structure And Permeability Of Ceramic Waste-based Permeable Bricks

As the refractory industrial solid waste,the annual emission of ceramic waster materials has been exceeded more than 10 million tons,which caused serious danger to ecological environment.In order to further promote the sustainable development and the construction of sponge city,it is urgent to reuse ceramic waste materials in a high economically way,especially in the bulk application of permeable bricks.In this paper,we used the ceramic waste materials as the basal skeleton to prepare the permeable bricks in high permeation of pavement,and its property is simulated and studied by optimizing the composition and process parameters The main works are as follows:In this part,we used solid phase sintering method to manufacture the permeable bricks.we systematic analyze the effect of content of aggregate,grain composition,mix of binder with coal gangue and magnesium slag,sintering temperature,forming pressure,soaking time,obtained the rule to the structure and performance of bricks.The result shown that the ceramic waste,composed with 2～3 mm and 1～2 mm,coal gangue and magnesium slag were mixed with 6:2:1:1 respectively,the performance of permeable brick was considered as appropriate under 6 MPa and sintered at 1200℃ for 1 h,the permeability,compressive strength and porosity were 1.56×10-2cm/s,35.45 MPa and 13.15%respectively.The permeability is 156%of the requirement of GB/T 25993-2010.The work offered the technical support for the construction of sponge city with total solid waste recycling.To improve the environmental stability and efficiency of application,choosing the water freezing-thawing,acid attack and acid freezing-thawing erosion conditions to study the structure and performance after 56 times cycle,showing that the mechanical properties still meet the requirements of GB/T 25993-2010.Among which the acid environment,the corrosion resistance was obviously better than that of the freeze-thaw environment.To further study the influence of components on the porous structure and performance,three oxides were introduced into brick,their effects were systematically considered on the structure and performance.Results shown that SiO2 guaranteed the compressive strength compared with Al2O3 and SiO2.The peanut shell was consumed as the pore-forming agent,preparing the brick with elliptical porous and low tortuosity structure.When the compressive strength reached the standard,the permeability was significantly increased to 2.58×10-2 cm/s,achieving the vast infiltration of rainfall about 150 mm/h.In order to analyze the relationship of structure and permeability,we established the model to explain of the infiltration process based on the fractal theory and the features such as tortuosity,porosity,and pore size,obtaining a theoretical coefficient that is in good agreement with the actual change of permeability coefficient.Using the simulating configuration method to build mathematical model,the mechanical performance of bricks was studied by finite element calculation and Griffth theory.At the case of similar tortuosity,the permeability is determined by porosity,and circular pores shown the best resistance to damage among the three holes pattern.