碱激发烧结砖粉力学性能与水化机理研究  

Research on mechanical properties and hydration mechanism of alkali-activated sintered brick powder

作　　者：马祖旭 于基宁[2] 杨华美 李丹[1] 魏厚振[4] 刘昊 MA Zuxu;YU Jining;YANG Huamei;LI Dan;WEI Houzhen;LIU Hao(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;China Railway First Survey and Design Institute Group Ltd,Xi an 710043,China;China Three Gorges Corporation Limited,Wuhan 430010,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)

机构地区：[1]武汉科技大学城市建设学院,湖北武汉430065 [2]中铁第一勘察设计院集团有限公司,陕西西安710043 [3]中国长江三峡集团有限公司,湖北武汉430010 [4]中国科学院武汉岩土力学研究所,湖北武汉430071

出　　处：《人民长江》2023年第6期200-207,共8页Yangtze River

基　　金：国家自然科学基金项目(41877260)。

摘　　要：废弃烧结砖约占城市建筑垃圾总量的50%,将其任意堆放与丢弃给环境造成极大负荷。为寻求废弃烧结砖的资源化利用新途径,以磨细的废弃烧结砖粉为原料,用水玻璃和NaOH为复合碱性激发剂制备碱激发胶凝材料,研究了水玻璃模数、Na_(2)O含量对碱激发烧结砖粉力学性能的影响,并结合水化热、X射线衍射和扫描电镜等测试技术,揭示了碱激发烧结砖粉的水化作用机理。结果表明:碱激发烧结砖粉抗压强度随水玻璃模数和Na_(2)O含量的增加均呈先增大后减小的变化趋势,当水玻璃模数为1.8、Na_(2)O含量3.0%时,试样28 d抗压强度最高,可达1.70 MPa,可做辅助胶凝材料使用。随着水玻璃模数减小或Na_(2)O含量增加,碱激发烧结砖粉浆体水化反应诱导期延长,加速期第二放热峰出现时间延后;放热总量随水玻璃模数减小而先增加后减小,随Na_(2)O含量增加而增加。碱激发胶凝材料微结构演变中,当水玻璃模数和Na_(2)O含量过高或过低时,均会阻碍水化产物N-A-S-H凝胶的生成,增加孔隙率,进而影响试样抗压强度的增长。The discarded sintered bricks account for about 50%of the total amount of urban construction waste,its improper and rampant disposal cause significant damage to the environment.In order to seek a new way of resource utilization of waste sintered bricks,the waste sintered brick powder was used as raw material,water glass and NaOH were used as composite alkaline activators to prepare alkali-activated cementitious materials.The influences of sodium silicate modulus and Na_(2)O content on the mechanical properties of alkali-activated sintered brick powder were studied,and the hydration mechanism of alkali-activated sintered brick powder was revealed by applying hydration heat,X-ray diffraction and scanning electron microscopy.The results showed that the compressive strength of alkali-activated sintered brick powder increased first,and decreased with the increasing of the sodium silicate modulus and Na_(2)O content.The 28 d compressive strength reached the maximum level up to 1.70 MPa when the sodium silicate modulus was 1.8 and the Na_(2)O content was 3.0%,which could be used as supplementary cementing materials.With the decreasing of sodium silicate modulus or the increasing of Na_(2)O content,the induction period of hydration reaction of alkali-activated sintered brick powder slurry was extended,and the appearance of the second exothermic peak during the acceleration period was delayed.The total heat release increased first and decreased with the decreasing of sodium silicate modulus,and increased with the increasing of Na_(2)O content.During the micro structure evolution of the alkali-activated cementitious materials,when the sodium silicate modulus and the Na_(2)O content were too high or low,the formation of the hydration product,i.e.N-A-S-H gel would be blocked,and the porosity increased,which would affect the growth of the samples compressive strength.

关 键 词：烧结砖粉 碱激发 水化热 抗压强度 水化机理 

分 类 号：TU522[建筑科学—建筑技术科学]