Study On Preparation Of Iron Tailing Foam Concrete And Shrinkage Performance

Iron tailing foam concrete is a new type of wall material,which has many excellent properties,but due to the performance of the defects in the structure,that has limited its wide application in construction industry.In this paper,foamed concrete of iron tailings was prepared by hydrogen peroxide foaming,and the effect of iron tailings powder,hydrogen peroxide,water cement ratio,coagulant,calcium stearate,sodium sulfate,fiber and cellulose on the mechanical contraction of iron tailings foam concrete physical properties,properties,microstructure and pore structure.Research results show that:With the increase of dosage of iron tailings powder(0%?40%),the setting time of foam concrete increases,the fluidity decreases,the compressive strength increases first and then decreases,the water absorption decreases,the shrinkage decreases first and then increases;With the increase of dosage of hydrogen peroxide(3.5%-6%),the compressive strength of iron tailings foam concrete increases first and then decreases,water absorption increases,shrinkage decreases first and then increases;With the increase of water cement ratio(0.30?0.50),the compressive strength of iron tailings foam concrete firstly increased and then decreased,water absorption fluctuated,shrinkage first decreased and then increased.When the coagulant dosage changes in the range of 0%?1.25%,the compressive strength of foam concrete increases,the water absorption decreases and the shrinkage decreases;When the foam agent amount changed within 0%?1%,the setting time of iron tailings foam concrete is prolonged,fluidity decreases,compressive strength increases first and then decreases,water absorption decreases and shrinkage decreases.When the amount of foam agent changed within 0%?1%,the setting time of iron tailings foam concrete is prolonged,fluidity decreases,compressive strength increases first and then decreases,water absorption decreases and shrinkage decreases;When the fiber content changes in the range of 0%?0.04%,the setting time of iron tailings foam concrete is shortened,fluidity decreases,compressive strength changes little,flexural strength increases obviously,water absorption increases,shrinkage decreases;When the cellulose content changes in the range of 0%?0.06%,the setting time of iron tailing foam concrete extension,the fluidity decreased,compared with the control group,the 3 d compressive strength decreased,28 d compressive strength increased first and then decreased,water absorption decreased,the shrinkage rate basically unchanged.The resonable ratio of iron tailings foam concrete is:with 30%iron ore tail,with 4%hydrogen peroxide,water cement ratio was 0.35 and with 0.75%accelerator,stabilizing agent mixed with 0.5%,with 1%early strength agent,fiber was 0.02%,with 0.02%cellulose,while the compressive strength is 2.6 MPa,the absorption rate was 31.3%,28 d shrinkage rate is 0.219%,the coefficient of thermal conductivity is 0.12 W/m·K.Microstructure shows,when the microstructure exists amount of ettringite.At the same time can form a mesh structure ettringite,Iron tailings foam concrete has higher compressive strength and lower shrinkage.Iron tailings powder,hydrogen peroxide,water cement ratio and coagulant are the main factors affecting the pore size of foam concrete,calcium stearate,sodium sulfate,fiber and cellulose has little effect on the stomatal pore.With the iron ore powder,the porosity will end cellulose calcium stearate,and apparent density decreases;With the increase of hydrogen peroxide,coagulant,sodium sulfate and fiber,and increase;With the increase of water cement ratio,it first increased and then decreased.The increase in the average aperture with the powder of iron tailings and calcium stearate and decreased first and then increased;With the increase of hydrogen peroxide and fiber,and increase;With the increase of water cement ratio,coagulant,sodium sulfate and cellulose,and reduce.