Research On The Preparation And Properties Of Foamed Concrete

The foam concrete was widely used in the construction field of our country due tothe characteristics of light weight and thermal insulation. It was signification to studydifferent cement-based foam concrete mix. According to the performance evaluationindex of foaming agent, the paper tested the performance index of the two differentfoaming agents and confirmed the corresponding dilution magnification. Based on theexperimental investigation of different cement-based foam concrete, the experimentmade sure the optimum w/c ratio, and researched on the basic performance.The results showed that the ordinary portland cement plant-foam concrete wasincorporated with plant foam, about10.5wt%of cement, and the optimum w/c ratiowas0.5~0.65. Ordinary portland cement animal-foam concrete was incorporated withanimal foam, about30wt%of cement, and the optimum w/c ratio was0.15~0.25.Sulphoaluminate cement animal-foam concrete mix was incorporated with animal foam,about35wt%of cement, and the optimum w/c ratio was0.1~0.4. When the water-cement ratio is0.65, ordinary portland cement plant-foam concrete can be prepared thedry apparent density295kg/m~3, the compressive strength0.26MPa, and thermalconductivity coefficient of0.075W/(m·K); the water-cement ratio was0.25, the animal-foam concrete can be prepared the dry apparent density254kg/m~3,28d compressivestrength of0.05MPa, and thermal conductivity coefficient of0.071W/(m·K). Thewater/cement ratio is0.2, the sulphoaluminate cement foam concrete can be preparedthe minimums dry apparent density233kg/m~3, compressive strength0.1MPa, thermalconductivity coefficient of0.069W/(m·K).The foam concrete mixed with fly ash not only can reduce the preparation cost, butalso can greatly decrease the dry apparent density of foam concrete, and furthermoreobtained excellent thermal performance. Animal foam concrete with fly ash content10wt%of cement, the corresponding dry apparent density reached the lowest192kg/m~3,reduced by36.8%than that without fly ash; plant foam concrete with the fly ash content10%~20wt%of cement, its lowest dry apparent density up to210kg/m~3, decreased by38.8%than the mix without fly ash. When the fly ash content was within20%and50%,sulphoaluminate cement foam concrete density fluctuated in the range of194~236kg/m~3,and as the fly ash content was30%, the dry apparent density reached the minimumvalue194kg/m~3, compressive strength0.09MPa, its minimum thermal conductivity0.053W/(m·K).The viscosity of foam concrete changed widely on the condition of low shear rate,the shear rate should be too quickly preventing the foam from vanishing. The resultsshowed that the ordinary portland cement foam concrete shear rate should be confinedto15s-1, and the sulphoaluminate cement foam concrete shear rate should be confined to20s-1. Fly ash may improve the slurry viscosity of foam concrete, and promote foam and cement paste wrapped, so fly ash was benefit to the preparation of foam concrete.