水泥–粉煤灰泡沫混凝土抗压强度与气孔结构的关系  

RELATIONSHIP BETWEEN COMPRESSIVE STRENGTH AND AIR-VOID STRUCTURE OF FOAMED CEMENT-FLY ASH CONCRETE

作　　者：方永浩[1] 王锐[1] 庞二波[1] 周玥 

机构地区：[1]河海大学力学与材料学院,南京210098

出　　处：《硅酸盐学报》2010年第4期621-626,共6页Journal of The Chinese Ceramic Society

基　　金：国家十一五科技支撑计划(2006BAJ04A04–02);江苏省自然科学基金(Bk2009345)资助项目

摘　　要：研究了粉煤灰和泡沫掺量对水泥–粉煤灰泡沫混凝土的干体积密度和抗压强度的影响,用读数显微镜和图像分析软件分析了泡沫混凝土的气孔结构,重点研究了泡沫混凝土的抗压强度与气孔结构关系。结果表明用粉煤灰取代水泥会降低泡沫混凝土的抗压强度,但其影响程度随混凝土气孔率的增大而减小:当粉煤灰取代率从20%(质量分数,下同)增加到50%时,不添加泡沫的混凝土的抗压强度从58.9MPa降低到了40.2MPa;气孔体积分数为0.27～0.30的1kg干胶凝材料(水泥加粉煤灰)添加600mL泡沫时,混凝土的抗压强度从32.7MPa降低到了23.6MPa,而气孔体积分数为0.62～0.66左右的1kg干胶凝材料添加2L泡沫时,混凝土的抗压强度仅从3.06MPa降低到2.47MPa,强度降低率分别为32.0%,28.0%和19.3%;泡沫混凝土的抗压强度与其基体的硬化水泥浆体强度、Feret孔径大于10μm的气孔的体积分数和形状因子具有良好的相关性。建立了泡沫混凝土的抗压强度与气孔结构参数的数学关系式。The effects of fly ash and foam volume on the dry apparent density and compressive strength of foamed cement-fly ash concrete were studied.The air-void structures of the foamed concretes were investigated by a reading microscope and image process software.The relationship between the compressive strength and the air-void structures was studied.The results show that replacement of cement with fly ash will reduce the compressive strength of the foamed concrete.When the replacement of cement with fly ash increased from 20%（in mass,the same below） to 50%,the compressive strength of the concrete without foam decreased from 58.9 to 40.2 MPa,and that of the concrete with the air-void fraction of 0.27–0.30 added with 600 mL foam in 1 kg dry binder,i.e.,the cement and fly ash,decreased from 32.7 to 23.6 MPa;while that of the concrete with the air-void fraction of 0.62–0.66 added with 2 L foam in 1 kg dry binder decreased only from 3.06 to 2.47 MPa;The strength reducing rates are 32.0%,28.0% and 19.3%,respectively;The compressive strength of the foamed cement-fly ash concrete is highly correlated to the air-avoid structure factors.A model describing the relationship between compressive strength and air-void structure parameters of the foamed concrete was proposed.

关 键 词：泡沫混凝土 强度 气孔结构 水泥 粉煤灰 

分 类 号：TU528[建筑科学—建筑技术科学]