硅酸盐通报2024，Vol.43Issue(6)：1965-1974,10.
低湿变温环境对硫酸盐作用下水泥砂浆性能的影响
Effect of Low Humidity and Varying Temperature Environment on Performance of Cement under Sulfate Attack
贾艳涛 1李之恒 2王大富 2吴萌2
作者信息
- 1. 河海大学力学与材料学院,南京 211100
- 2. 东南大学材料科学与工程学院,南京 211189
- 折叠
摘要
Abstract
Based on environmental characteristics of reinforced concrete infrastructure in western China,cement mortar specimens were subjected to semi-immersed sulfate corrosion in low humidity and varying temperature.The influences of low humidity and varying temperature on semi-immersion sulfate attack cement-based materials were studied by combination of XRD,SEM,LF-NMR,and conductivity titration of sulfate ions.The results show that under low humidity and varying temperature,the mortar subjected to semi-immersion sulfate attack has a water film zone within 30 mm above the surface of sulfate solution,and the corrosion degree is relatively low.The evaporation zone above the solution surface of 30～60 mm has a higher degree of corrosion and obvious peeling phenomenon.Corrosion of evaporation zone of mortar semi-immersed in Na2SO4 solution is more seriously than that semi-immersed in MgSO4 solution due to their difference in saturation under different temperatures.The expansive salt crystallization within pores above 1 000 nm is prone to the occurrence in evaporation zone,which leads to the micro cracks inside mortar and an increase in the proportion of harmful pores,resulting in physical expansion damage being the main cause of this zone.Chemical corrosion in the immersion zone of mortar is dominant due to the formation of swelling corrosion products such as gypsum and ettringite.As corrosion products accumulated in the pores with pore sizes of 50～1 000 nm,the surface of mortar cracks and the proportion of macroscopic pores with pore sizes above 1 000 nm increases.The addition of ground granulated blast furnace slag in cement increases the sulfate corrosion resistance of the immersion zone of mortar via its secondary hydration effect,and the addition of limestone powder decreases the sulfate corrosion resistance of mortar due to its dilution effect.关键词
矿物掺合料/温度/硫酸盐腐蚀/SO42-/孔径分布Key words
mineral admixture/temperature/sulfate corrosion/sulfate ion/pore size distribution分类
建筑与水利引用本文复制引用
贾艳涛,李之恒,王大富,吴萌..低湿变温环境对硫酸盐作用下水泥砂浆性能的影响[J].硅酸盐通报,2024,43(6):1965-1974,10.
