氢氧化钡对水泥砂浆抗硫酸盐侵蚀性能的影响  

Effect of Barium Hydroxide on Sulfate Resistance of Cement Mortars

作　　者：李长江 LI Changjiang(Central China Normal University,Wuhan 430000,China)

机构地区：[1]华中师范大学基建处,湖北武汉430000

出　　处：《粉煤灰综合利用》2022年第4期42-47,共6页Fly Ash Comprehensive Utilization

基　　金：国家自然科学基金(51708240)。

摘　　要：硫酸盐侵蚀是影响混凝土耐久性的重要因素之一。本文通过砂浆质量、超声波传播速度、抗压强度等宏观性能研究了不同氢氧化钡掺量对砂浆试件抗硫酸盐侵蚀性能的影响,并基于差示量热分析(DSC-TG)和X-射线衍射分析(XRD)对侵蚀产物相进行分析,探究氢氧化钡掺量对其抗侵蚀性能的影响机制。研究结果表明:在硫酸钠侵蚀环境下,早期形成的石膏类侵蚀产物会填充在水泥基材料的孔隙中,导致质量、超声波传播速率和抗压强度呈现早期增长,后期大量石膏的形成会导致其宏观性能快速降低;氢氧化钡掺量在1%以内时能够提高砂浆的抗硫酸盐侵蚀性能,当氢氧化钡掺量为1.5%时,砂浆的抗硫酸盐侵蚀性能急剧下降;掺入一定量的氢氧化钡能够与侵入的硫酸根离子发生反应形成BaSO_(4),可降低侵蚀产物石膏的形成,使其抗侵蚀性能得到了提升。Sulfate attack is one of the important factors that affect the durability of concrete.In this paper, the influence of different barium hydroxide content on the sulfate attack resistance of mortar was studied through the macro properties of mass change, ultrasonic propagation speed and compressive strength.The corrosion products were analyzed by differential scanning calorimetry(DSC-TG) and X-ray diffraction(XRD).The influence mechanism of barium hydroxide content on its corrosion resistance was further discussed.The results show that gypsum formed in the early stage will fill the pores of cement-based materials, leading to the early increase of mass, ultrasonic propagation speed and compressive strength.The formation of a large amount of gypsum in the later stage will lead to the rapid decline of macro properties, when the content of Ba(OH)is less than 1%,the sulfate resistance of mortar can be improved.When the content of Ba(OH)is up to 1.5%,performance of mortars decrease rapidly.The addition of Ba(OH)can react with sulfate ions to form BaSO_(4),resulting in the improvement of its erosion resistance.

关 键 词：硫酸盐侵蚀 氢氧化钡 石膏 砂浆 

分 类 号：TU528.01[建筑科学—建筑技术科学]