改性高钙灰对水泥基材料的抗酸腐蚀特性  

Effects of Modified High-Calcium Fly Ash on Anti-Acid Corrosion Characteristics of Cement Material

作　　者：马保国[1] 肖君[1] 汪海贵[1] 王凯[1] 

机构地区：[1]武汉理工大学硅酸盐材料工程教育部重点实验室,湖北武汉430070

出　　处：《济南大学学报（自然科学版）》2009年第1期4-8,共5页Journal of University of Jinan(Science and Technology)

基　　金：国家863计划(2005AA332010)

摘　　要：模拟中国硫酸型酸雨情况,以普硅水泥空白砂浆为参比体系,研究改性高钙粉煤灰对改善混凝土抗酸性能的影响,从宏观和微观方面研究各性能变化规律。结果表明:高钙粉煤灰对建筑物抗酸腐蚀有优化效果,但掺量存在最佳优化区间和"拐点";掺量w(高钙灰)=25%的砂浆腐蚀98 d后质量损失率仅-2.011%,而相同腐蚀条件下空白砂浆的质量损失率为-5.120%;98 d抗压强度和抗折强度是空白砂浆的1.31倍和1.47倍;机理分析发现高钙灰中大量的活性钙可作为缓冲组分,减缓体系由碱性环境变成酸性或中性环境的速度,从而阻止其他水化产物因pH值降低而产生的不稳定溶蚀现象;微细CaO颗粒会反应生成CaSO4沉积在试块表面,既解决膨胀破坏问题又堵塞了酸液的入侵通道。Taking ordinary portland cement as the contrastive system, the experiment simulated Chinese sulfate acid rain situation and investigated the ability of modified high-calcium fly ashes to improve the concrete property of resisting acid rain. Through macroscopic and microscopic test methods we studied the change role of various properties. The results showed that the modified high-calcium fly ash has the optimal effect of resisting acid rain and also has the optimal interval and inflection point. When the mortars with w =25% modified high-calcium fly ash has heen soaked in the simulated acid rain environment for 98 d,its mass rate was only -2.011% , while the mass loss rate of blank cement mortar was -5. 120% （under the same conditions） ;its compressive strength and flexural strength were 1.31 times and 1.47 times of the blank cement mortar. Mechanism analysis indicated that the massive active calcium in the high - calcium fly ash can be used as the buffer component, and slow down the system speed of turning from alkaline to acid or neutral, thus prevent other hydration products corrode due to the low pH value. The fine CaO particles in the high-calcium fly ash could form CaSO4 that deposits on the surface of test block, which will solve the problem of expansive destruction and block the entering channel of acid.

关 键 词：高钙粉煤灰 酸雨 拐点 质量损失率 抗压强度损失 抗折强度损失 SEM显微分析 

分 类 号：TU528.33[建筑科学—建筑技术科学]