CaO增强复合胶凝材料的性能  

Performance of CaO Reinforced Composite Cementitious Materials

作　　者：郭磊[1,2,3,4] 王泽坤 郭利霞 陈平平[1] 汪伦焰 李明儒 王卫凯[1] GUO Lei;WANG Zekun;GUO Lixia;CHEN Pingping;WANG Lunyan;LI Mingru;WANG Weikai(School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450046,China;Henan Water Valley Research Institute,Zhengzhou 450046,China;Henan Key Laboratory of Water Environment Simulation and Treatment,Zhengzhou 450002,China;Henan Water Conservancy Investment YuYuan Water Ecology Co.Ltd.,Pingyu 463400,China)

机构地区：[1]华北水利水电大学,郑州450046 [2]河南水谷研究院,郑州450046 [3]河南省水环境模拟与治理重点实验室,郑州450002 [4]河南水投舆源水生态有限公司,平舆463400

出　　处：《材料研究学报》2022年第4期278-286,共9页Chinese Journal of Materials Research

基　　金：河南省自然科学基金(202300410270);华北水利水电大学研究生教育创新计划基金(YK2020-04);河南省水利科技攻关项目(GG202040)。

摘　　要：使用重金属污泥制备免烧砖。使用CaO钙源优化配置复合胶凝材料的组分,并调控胶凝浆体中的水化产物和未水化相。先基于免烧砖原料的配合比计算复合胶凝体系的钙硅比(Ca/Si)并控制其值为0.8~1.2,设计添加CaO的免烧砖实验方案。使用核磁共振(NMR)、透射电镜-能谱等手段和PCAS分析软件,研究了CaO使高硅复合胶凝材料性能提高的机理。结果表明:随着高硅胶凝体系Ca/Si比在0.8~1.2范围内的提高,免烧砖的力学性能先提高后降低,Ca/Si比的最佳值为1.0,CaO也有一个最佳调控值。随着Ca/Si比的提高7 d试样的吸水率先降低后提高,28 d试样的吸水率线性降低。随着Ca/Si比的提高,试样中平面孔径大于200μm的孔隙率递减,分形维数先减小后增大;对于孔径小于200μm的孔结构,随着Ca/Si比的提高孔径为200~200μm的孔减少,孔径小于200 nm的孔增多,孔的体积呈减小的趋势。复合胶凝体系能抑制污泥免烧砖70%以上的重金属浸出量。Unburned brick was prepared with sludge containing heavy metals as raw material,and CaO as calcium source to optimize the composition of the composite cementitious material and to regulate the hydration products and unhydrated phases in the cementitious slurry.First,the Ca/Si ratio(Ca/Si)of the composite cementitious system was calculated based on the mix ratio of raw materials of unfired bricks.Then,an experimental scheme of unfired bricks with varying amount of CaO was designed,and the Ca/Si ratio was quantitatively controlled within the range of 0.8~1.2.The mechanism of CaO improving the properties of high silicon composite cementitious materials was investigated by means of transmission electron microscopy(TEM)and energy spectrum(EDS)and PCAS software.The results show:with the increasing Ca/Si ratio within the range of 0.8~1.2,the mechanical properties of the unfired brick enhance first and then decrease.The optimal value of Ca/Si is 1.0,and there is also an optimal control value of CaO;With the increasing Ca/Si ratio,the water absorption decreases firstly and then increases for the bricks on the 7th day after they were made,and the water absorption decreases linearly for those on the 28th day;With the increasing Ca/Si ratio,the porosity of the plane pore size greater than 200μm decreases for the prepared bricks,and the fractal dimension decreases first and then increases;For the pore size smaller than 200μm,with the increase of Ca/Si,the pore size between 200 nm~200μm decreases,and the pore size smaller than 200nm increases,while the pore size decreases;and Last but not least,the leaching amount of heavy metals from the unburned bricks can be inhibited up to more than70%by the formed composite cementitious material.

关 键 词：复合材料 免烧砖 钙硅比 污泥 力学性能 

分 类 号：TU526[建筑科学—建筑技术科学]