摘要
为寻找高成本硅质骨料的替代品并提高高硅型铁尾矿砂利用率,以高硅型铁尾矿砂与粉煤灰复掺替代硅砂制备蒸压加气轻质混凝土(ALC)试件,分析了铁尾矿砂/粉煤灰混合比例及水胶比对蒸压加气轻质混凝土性能的影响规律,并采用XRD及SEM等手段对水化产物和微观结构进行分析。结果表明:随着铁尾矿砂占比的增大,试件的干体积密度逐渐增大,抗压强度先增大后降低;随着水胶比的增大,试件的干体积密度和抗压强度逐渐降低。当铁尾矿砂、粉煤灰、水泥、石灰及脱硫石膏质量比为62.8∶9.0∶16.9∶8.9∶2.4时,控制水胶比为1.40,所制备的试件抗压强度为4.15 MPa、干体积密度为576 kg/m^(3),满足《蒸压加气混凝土砌块》(GB/T 11968—2020)规定的强度等级A3.5、干体积密度等级B06的要求。XRD结果显示主要水化产物为石英、托贝莫来石、硅钙水合物及沸石,SEM分析进一步说明水化形成大量板状的托贝莫来石及少量C—S—H凝胶,良好的网状结构使得承压时不易引起应力集中。
In order to find a substitute of high-cost silica aggregate and improve the utilization rate of high-silicon iron tailings,the autoclaved aerated lightweight concrete(ALC)was prepared by mixing high-silicon iron tailings and fly ash instead of silicon sand,and the influence of the mixing ratio of iron tailings with fly ash and water-binder ratio on the performance of autoclaved aerated lightweight concrete were analyzed.XRD and SEM were used to analyze the hydration products and microstructure.The results showed that the dry volume density of specimen increases gradually,and the compressive strength increases first and then decreases with the increase of iron tailings proportion.With the increase of water-binder ratio,the dry volume density and compressive strength of the specimen decrease gradually.When the mass ratio of iron tailings,fly ash,cement,lime and desulfurized gypsum is 62.8∶9.0∶16.9∶8.9∶2.4 and the water-binder ratio is 1.40,the compressive strength and dry volume density of the specimen prepared are 4.15 MPa and 576 kg/m^(3),which meets the requirements of strength grade A3.5 and dry volume density grade B06 in stipulated of Autoclaved Aerated Concrete Block(GB/T 11968—2020).XRD results showed that the main hydration products are quartz,tobermorite,silica-calcium hydrate and zeolite.SEM analysis further showed that a large number of plate-like tobermorite and a small amount of C-S-H gel are formed during hydration.The good network structure makes it difficult to cause stress concentration under pressure.
作者
顾晓薇
王屾宇
刘剑平
宁宝宽
刘朋
张延年
GU Xiaowei;WANG Shenyu;LIU Jianping;NING Baokuan;LIU Peng;ZHANG Yannian(Technology Innovation Center for Intelligent Water Resources and Environment,Northeastern University,Shenyang 110819,China;School of Architecture and Civil Engineering,Shenyang University of Technology,Shenyang 110870,China;School of Civil Engineering,Shenyang Jianzhu University,Shenyang 110168,China)
出处
《金属矿山》
CAS
北大核心
2022年第1期35-40,共6页
Metal Mine
基金
“十三五”国家重点研发计划项目(编号:2019YFC1907202)
国家自然科学基金面上项目(编号:52074061)
国家自然科学基金面上项目(编号:51974060)
国家自然科学基金联合基金项目(编号:U1903216)
辽宁省重大科技专项(编号:2020JH1/10300005)
辽宁省“兴辽英才计划”项目(编号:XLYC1905016)。
关键词
高硅型铁尾矿
蒸压加气轻质混凝土
混合比例
水胶比
流动性
抗压强度
干体积密度
水化
产物
high-silicon iron tailings
autoclaved lightweight concrete
mixing ratio
water-binder ratio
fluidity
compres-sive strength
dry volume density
hydration products
