冻融循环作用下锂渣混凝土抗硫酸盐侵蚀研究

Study on the Sulfate Corrosion Resistance of Concrete with Lithium Slag under the Freezing and Thawing Cycles

基于锂渣的微集料效应和活性效应研究了冻融循环作用下锂渣不同掺量对混凝土的抗硫酸盐侵蚀性能,同时利用扫描电镜和压汞法探究分析了冻融循环作用下锂渣混凝土在硫酸盐侵蚀作用下的形貌变化和孔结构变化。结果表明:锂渣能有效增加混凝土在冻融循环作用下的抗硫酸盐侵蚀,且随着锂渣掺量的增加,混凝土的抗硫酸盐侵蚀性能越优;冻融循环作用下混凝土在硫酸盐溶液中生成的腐蚀产物是钙矾石,;掺加锂渣能有效改善混凝土的孔结构,掺加30%锂渣混凝土在硫酸盐溶液中冻融循环420次之后的孔隙率为17. 9%,而不掺加锂渣混凝土的孔隙率为29. 1%。

The corrosion resistance of concrete of different lithium slag content under the freezing and thawing cycles is studied,based on the micro aggregate effect and active effect of lithium slag.The changes of morphology and pore structure of concrete with lithium slag under sulfate attack were analyzed by scanning electron microscope(SEM),mercury intrusion porosimetry(MIP).The results show that the lithium slag can increase the sulfate resistance of concrete in freeze-thaw cycles effectively,and with the increase of the lithium slag content,the sulfate resistance of concrete is excellent;The corrosion product of concrete exposed to the 5%Na 2SO 4 solution under freezing and thawing cycles is ettringite;The porosity of concrete is improved by adding lithium slag effectively.The porosity of concrete with 30%lithium slag is 17.9%after freezing and thawing 420 cycles in 5% Na2 SO4 solution,and the porosity of concrete without lithium slag is 29.1%.