再生砂粉基发泡混凝土性能研究

Research on the performance of recycled sand powder-based foamed concrete

利用筑垃圾破碎后筛分出的再生砂粉细骨料制备设计密度等级为A11的发泡混凝土,研究了再生砂粉及泡沫掺量等因素对发泡混凝土力学性能、干密度及导热系数等性能的影响规律。研究结果表明,随着再生砂粉掺量的增加,发泡混凝土干密度在1086.1~1172.3 kg/m^(3),抗压强度等级从FC5下降到FC2,导热系数均≤0.27 W/(m·K);再生砂粉基发泡混凝土的抗压强度、干密度和导热系数随泡沫掺量的增加均呈现下降趋势。其中干密度等级从A13减小到A9,当泡沫掺量在7%时,抗压强度仅为0.6 MPa;对比分析再生砂粉取代率和泡沫掺量对发泡混凝土吸水率的影响规律,其吸水率均随着两者掺量的增加而增大,但泡沫掺量对其影响更为显著;此外,通过强度-成本比率,确定密度等级为A11的再生砂粉基发泡混凝土,即再生砂粉取代率为20%时,单位成本下获得的RSPFC抗压强度最高。

The effect of recycled sand powder and foam admixture on the mechanical properties,dry density and thermal conductivity of foamed concrete was studied.The results showed that with the increase of recycled sand powder,the dry density of foamed concrete ranged from 1086.1 kg/m^(3) to 1172.3 kg/m^(3),the compressive strength grade decreases from FC5 to FC2,and the thermal conductivity is≤0.27 W/(m·K).The compressive strength,dry density and thermal conductivity of recycled sand powder-based foamed concrete(RSPFC)showed a decreases trend with the increases of foam admixture.The compressive strength is only 0.6 MPa when the foam admixture is at 7%.The water absorption rate of the foamed concrete increases with the increases of both admixture rates,but the foam admixture rate have a more significant effect on it.In addition,the highest compressive strength of RSPFC per unit cost was determined by the strength to cost ratio for the recycled sand powder-based foamed concrete with density class A11,the highest compressive strength of RSPFC per unit cost is obtain when the replacement rate of recycled sand powder is 20%.