粉煤灰对再生混凝土抗硫酸盐侵蚀及界面过渡区微观特性的影响  

The Influence of Fly Ash on Resistance to Sulphate Erosion and the Microstructure of Interfacial Transition Zone of Recycled Concrete

作　　者：朱晓云[1] 孙国卿[2] 

机构地区：[1]天津交通职业学院,300110 [2]天津大学仁爱学院,301636

出　　处：《混凝土与水泥制品》2019年第5期92-96,共5页China Concrete and Cement Products

摘　　要：为了探究硫酸盐侵蚀作用下粉煤灰再生混凝土性能的变化,测试了材料配比对混凝土抗压耐蚀系数和质量损失率的影响,得到合理的材料组成,并通过SEM观察再生混凝土中老骨料-新浆体、老浆体-新浆体和老骨料-老浆体三种界面过渡区的微观形貌,解释了粉煤灰对再生混凝土抗硫酸盐侵蚀的改善机理。结果显示,增大水胶比和再生骨料替代率都会削弱混凝土的抗硫酸盐侵蚀性能,而粉煤灰的掺入能明显提高混凝土的抗硫酸盐侵蚀能力。最终确定的水胶比为0.55,再生骨料替代率和粉煤灰掺量分别为50%和30%。老骨料-新浆体界面和老骨料-老浆体界面是粉煤灰再生混凝土中的双重薄弱面,在制备时需重点处理。In order to investigate the change of the performance of fly ash recycled concrete under the action of sulfate erosion, the effects of material ratio on the corrosion resistance coefficient and quality loss rate of concrete were tested and reasonable material composition was obtained. The microstructures of three interfacial transition zones of old aggregate-new slurry, old slurry-new slurry and old aggregate-old slurry in recycled concrete were observed by SEM. The results show that increasing the W/B and the replacement rate of recycled aggregate will weaken the sulfate corrosion resistance of concrete, but the addition of fly ash can obviously improve the performance of concrete against sulfate erosion. The W/B, the substitution rate of recycled aggregate and the amount of fly ash were determined by 0.55, 50% and 30 % respectively. The interface between old aggregate and new slurry, old aggregate and old slurry is the double weak surface in fly ash recycled concrete, so it should emphasis on preparation.

关 键 词：再生混凝土 粉煤灰 抗硫酸盐侵蚀 界面过渡区 微观形貌 

分 类 号：TU528[建筑科学—建筑技术科学]