Study On The Effect Of Roasted Iron Tailings On The Performance Of Permeable Brick

With the rapid development of urbanization in our country,the area of urban impervious pavement is increasing day by day,resulting in the phenomena of "urban heat island effect" and "city looking at the sea",which bring inconvenience to urban construction and people's life.Therefore,the construction of "sponge city" is of vital importance.As a kind of green building material,permeable brick can use its own good permeability to solve the negative impact of impervious pavement.Iron tailings have the characteristics of large output and low comprehensive consumption rate.A large amount of tailings accumulation has caused environmental pollution and land waste.Therefore,this topic uses large amount of tailings as aggregate and roasted tailings as cementing material to prepare permeable bricks,which solves the problems of tailings accumulation and poor strength of tailings bricks.Using calcined tailings,cement and a small amount of fly ash as cementitious materials,taking single particle size +2.36-4.75 mm iron tailings as aggregate,through aggregate surface wrapping method,vibration forming process and standard curing method,the concrete forming and curing are carried out,and the preparation process of permeable brick is designed by equal volume method.The effects of the amount of calcined tailings,vibration time,water binder ratio and target porosity on the mechanical properties and permeability coefficient of permeable bricks were investigated,and the preparation process parameters of permeable bricks were optimized.The hydration products,micro morphology and pore characteristics of permeable bricks were studied by XRD,SEM,measured porosity and apparent pore analysis.In addition,the differences of mechanical properties and water permeability between calcined and unburned tailing bricks are analyzed.The conclusion of the test is that under the condition that the calcined tailings account for 60% of the cementation materials,the flexural and compressive strength of the permeable bricks are 3.34 Mpa and 15.44 Mpa respectively,and the permeability coefficient is 2.58×10-2 cm/s,which conforms to the national standard grade A standard.Figure 43;Table 16;Reference 81...