With the in-depth promotion of China's"Western Development"and"Belt and Road"develop-ment strategies,construction in permafrost regions is increasing.The negative effects of negative tempera-ture degradation and sulfate attack on the performance of cement slurry have brought potential safety haz-ards to engineering construction.In this paper,the hydration products,pore structure and mechanical prop-erties of cement slurry were analyzed by XRD,SEM,TG,CT and mechanical test through the hydration test of cement slurry without precuring at-20 ℃.The effect of CaCl2-BaCl2 compound on the hydration performance of cement slurry under negative temperature and sulfate environment was comprehensively e-valuated.The experimental results show that compared with the single use of CaCl2,the addition of BaCl2 can not only promote the hydration degree of cement slurry,but also react with SO42-,reduce the formation of ettringite(also known as calcium aluminite,AFt),and improve the resistance of cement slurry to sulfate attack.When CaCl2-BaCl2 is used in combination,the reasonable dosage of BaCl2 is 10wt％-15wt％.At this time,the cement slurry has relatively optimal hydration products,pore structure and mechanical prop-erties,and its resistance to negative temperature degradation and sulfate attack is also significantly im-proved.The research results can provide theoretical reference and technical reference for engineering con-struction in frozen soil area.
关键词
水泥浆/负温劣化/硫酸盐侵蚀/CaCl2-BaCl2复配/水化性能评价/试验研究
Key words
cement slurry/negative temperature deterioration/sulfate attack/CaCl2-BaCl2 compound/hydra-tion performance evaluation/experimental investigation
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