超细矿渣和超细偏高岭土对砂浆抗盐侵蚀性能的影响

王学明,朱梦伟,袁 俊*,魏 鹏

 

超细矿渣和超细偏高岭土对砂浆抗盐侵蚀性能的影响

王学明,朱梦伟,袁 俊*,魏 鹏

(中国电力工程顾问集团西北电力设计院有限公司,陕西 西安  710075)

摘  要  选用超细矿渣和超细偏高岭土配制水泥砂浆,采用早期湿养护的方式分别养护至3 d和7 d,并对达到28 d龄期的所有砂浆试件分别进行标准养护和硫酸盐半浸泡实验,实验龄期为+28 d、+56 d和+90 d。分析了早期湿养护对砂浆试件抗压、抗折强度及抗硫酸盐侵蚀性能的影响。分析结果表明,掺超细矿渣和超细偏高岭土均可以增加砂浆的抗压强度,但对提升砂浆的抗折强度效果并不明显;掺超细矿渣和超细偏高岭土可有效地减小在半浸泡条件下砂浆抗折强度及抗折强度损失率对早期湿养护时间的敏感度,提高砂浆的抗硫酸盐侵蚀能力;对比而言,超细矿渣对于改善砂浆的抗硫酸盐侵蚀性能的效果不佳,其掺量不宜超过10%,且早期湿养护时间也不应低于7 d。而掺超细偏高岭土的砂浆,即使早期湿养护时间只有3 d时,也可以显著改善砂浆的抗硫酸盐侵蚀性能。

关键词    超细矿渣;超细偏高岭土;砂浆;硫酸盐侵蚀;半浸泡

中图分类号:TU521;TQ177.6;TQ172.4+4;P575.2   文献标识码:A    doi:10.3969/j.issn.1000-6281.2019.03.006

 

The effects of ultra-fine ground granulated blast-furnace slag and ultra-fine metakaolinon salt erosion resistance of mortar

WANG Xue-ming,ZHU Meng-wei,YUAN Jun*,WEI Peng 

(Northwest Electric Power Design Institute Co., Ltd. of China Power Engineering Consulting Group,Xi’an Shaanxi 710075, China)

Abstract  The ultra fine GGBS (UFS) and ultra fine metakaolin (UFMK) were used to prepare cement mortars under moist curing at early ages of 3 d and 7 d. The mortar specimens were then cured under standard curing condition or sulfate partial soaking at 28 d. The experimental ages were +28 d, +56 d and +90 d. The influence of moist curing time at early ages on the compressive and flexural strengths, and the resistance to sulfate attack of mortar was investigated. The results show that the compressive strength of mortars is improved by adding UFS and UFMK. However, the improvement on the flexural strength is not obvious. Meanwhile, the flexural strength loss due to sulfate partial soaking can be effectively reduced by adding UFS and UFMK. The sensitivity of flexural strength loss rate to moist curing time was reduced andthe resistance to sulfate erosion of mortar was improved. In contrast, the UFS has little effect on improving the resistance to sulfate attack of mortar. The dosage of UFS should not exceed 10% and the moist curing time should not be less than 7d for UFS-cement mortars. However, the cement mortar with UFMK can significantly improve the resistance to sulfate attack even if the moist curing time is only 3d.

Keywords  ultra-fine ground granulated blast-furnace slag;ultra-fine metakaolin;mortar;sulfate attack;partial soaking

 

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