Experimental Study On Preparation Of Foam Concrete Making Use Of Regenerated Powder

With the rapid development of China’s social economy, urbanization process accelerated,a large number of construction waste produced by reconstruction, expansion and demolitionengineering become difficult to deal with waste resources. Waste concrete after sorting,crushing, fine grinding and other means, can get recycled aggregate and recycled powder,recycled aggregate can be used to prepare recycled concrete, but the reuse of recycled finepowder has not been resolved. Therefore, the research of recycled fine powder preparation offoamed concrete, not only in response to the national policy calls for the country in recentyears about building materials energy saving and waste, but also has the outstanding producteconomic and social benefits.A lot of experiments are conducted to study the foam agent system, cementitiousmaterial system and admixture system which has the effect on its properties. Firstly, thereference mix ratio of foamed concrete is determined by choosing the foam system. On thisbasis, adding regenerated powder as cementitious material, and use the activator to stimulateits activity. And then, experimental study on admixture system. Finally, optimize the mixproportion based on the orthogonal experiment results and prepared the regeneration powderfoam concrete to meet industry standards.The main conclusions of this paper are as follows:(1)When using commerciallyavailable plant source protein foaming agent, the dilution proportion was1:40;Hydroxypropyl methyl cellulose ether as stable agent, the mixing proportion is0.08%, at thistime, constitute a stable foam system, the foaming multiple of34.6times, subsidence distanceis11.5mm, the bleeding is15.5mL, can be used to prepare recycled powder foam concrete.(2)Using15%recycled powder instead of cement, adding25%gypsum as sulfate activatorwith1.2%poly carboxylic acid water reducer, at this time, regeneration powder foamconcrete work is good, easy molding and no collapse.(3)Selection of lithium carbonate as theincorporation of inorganic salt, optimal dosage is0.3%; calcium stearate as hydrophobic agentmixed into, optimal dosage is1.5%. At this time, the regenerating powder foam concretesetting time was shortened and the sharp decline in the water absorption rate, and its use effect is improved.In this paper, the recycled fine powder foamed concrete is developed, and itsperformance is the index of: The dry apparent density was625.07kg/m3,28d compressivestrength was4.7Mpa and water absorption rate of22.93%,15times after freezing andthawing mass loss is3%, the strength loss is11%, coefficient of thermal conductivity was0.131, meet the requirements of B06and A3.5in JC/T1062-2007Foam Concrete Block, canbe used as wall heat preservation material, and have good use effect and economy.