Research On Improvements Of Performances Of Foamed Concrete And Improving Mechanism

Foamed concrete as a new type of energy saving and environment-friendly buildingmaterials, which preparation and properties are more and more people’s attention. Thence,Preparation of high strength, low density, lower dry shrinkage and low water absorptionfoamed concrete is very urgent.Using stone powder and sands as filled parts of concrete, and successfully prepares akind of concrete by adding different proportion of soda residue, polypropylene fiber,polymer (rubber powder and epoxy resin emulsion) and suspending agent. Then tests thedensity, compressive strength, flexural strength, water absorption and shrinkage ofdifferent concrete, and analyzes the influences of different fibers and polymers onproperties of concrete. The paper tests the porosity, pore size distribution and poremorphology of different concrete by the method of mercury porosimetry.The experiments of foamed concrete with different proportions of polypropylenefiber show that, polypropylene fiber can obviously enhance the toughness and strength ofconcrete, and can more or less decrease the shrinkage during the harden process ofconcrete. The strength of foamed concrete decreases as the proportion of filled parts of itincreases.The experiments of foamed concrete with different proportions of rubber powdershow that, rubber powder can obviously enhance the toughness and strength of concrete.Meantime, the average size of pore in foamed concrete hardened paste decreases, theporosity increases. The foamed concrete containing rubber powder shows the shrinkageand water absorption appears to be increases as the hydration goes on.The experiments of foamed concrete with different proportions of epoxy resinemulsion show that, proper dosages of epoxy resin emulsion can obviously enhance thetoughness and strength of concrete. The porosity desreases, the shrinkage appears to beincreases as the hydration goes on, the water absorption decreases.The polymer form a network structure within the foamed concrete, cement hydratesand the polymer intertwined together, thus improving the structure and morphology ofthe foamed concrete. Mixing a certain number of fibers, polymers can be optimizedfoamed concrete structure, To overcome the shortcomings and deficiencies of the foamedconcrete, comprehensive performance of insulation materials.