大掺量火山灰泡沫混凝土的制备及性能优化

采用天然火山渣经磨细处理后得到的火山灰和水泥作为胶凝材料,通过化学发泡的方法,制备了700级大掺量火山灰发泡混凝土,研究了不同组成和养护条件对火山灰泡沫混凝土的成型状态、干密度及抗压强度的影响。结果表明,当胶凝材料总量为700 g(火山灰占70%)、水胶比为0.3、早强剂(CaCl2)掺量为1.8%、稳泡剂(硬脂酸钙)掺量为0.6%、H2O2掺量为1.5%,减水剂掺量为0.2%,并在85 ℃条件下蒸养24 h时,制备出的700级大掺量火山灰泡沫混凝土性能最佳,其成型状态良好、干密度为650 kg/m^3、抗压强度为6.6 MPa、导热系数为0.144 3 W/(m·K)。

Preparation and Performance Optimization of Foamed Concrete with High Content of Volcanic Ash

High volume volcanic ash foam concrete (700 kg/m^3) is prepared by chemical foaming method using volcanic ash obtained by grinding the natural volcanic slag and cement as cementing material of which the volcanic ash accounts for 70%.The results show that when using 700 g cementing material,0.3 water binder ratio,1.8% early strength agent (CaCl2),0.6% foam stabilizer(calcium stearate),1.5% H2O2,0.2% water reducing agent,the high volume volcanic ash foam concrete reaches to the best properties under the curing condition with 85 °C for 24 h.The forming state is good;dry density is 650 kg/m^3,compressive strength is 6.6 MPa,and thermal conductivity is 0.144 3 W/(m·K).