摘要
气泡混合轻质土的孔隙率高,处于地下水位以下时,随着时间的推移其部分孔隙会被水填充,使其丧失轻质特性,进而威胁到工程安全,所以研究如何降低气泡混合轻质土的吸水性很有必要。分别制备了掺入憎水剂、减水剂、早强剂和粉煤灰(内掺和外掺)的气泡混合轻质土试样,通过吸水性试验和相容性试验研究了掺入不同外加剂对于降低气泡混合轻质土吸水性的效果,并分析了外加剂与气泡混合轻质土之间的相容性问题。试验结果表明,掺入适量的憎水剂、减水剂、早强剂和粉煤灰都能降低气泡混合轻质土的吸水性,但降低效果各不相同。内掺10%的粉煤灰时降低气泡混合轻质土的吸水性效果最佳,可将气泡混合轻质土的吸水率降低4.8%,且内掺粉煤灰不仅可以降低气泡混合轻质土的吸水率,还可以在一定程度上替代水泥的作用,节省造价,在工程中具有更好的实用性。掺入减水剂后消泡现象明显,导致制备的气泡混合轻质土密度明显增大,所以掺入减水剂对于降低气泡混合轻质土的吸水性效果最差。虽然掺入适量的憎水剂和早强剂也可以降低气泡混合轻质土的吸水率,但效果有限,且也会因为相容性问题引起消泡进而造成土体密度的明显增大。
The porosity of the air-foam treated lightweight soil is high. When air-foam treated lightweight soil is lower than the groundwater level,part of its pores will be filled with water and its lightweight feature will not work with elapsed time,threatening the safety of the project. Therefore,it is necessary to study how to reduce the water absorption of air-foam treated lightweight soil. In this study,the air-foam treated lightweight soil samples were prepared with water-repellent admixture,water reducing agent,early-strength admixture and fly ash(mixed in and out). Through the water absorption and compatibility tests,the effect of different admixtures on reducing the water absorption of air-foam treated lightweight soil was studied,and the compatibility between the admixture and the bubble mixed lightweight soil is analyzed. The experimental results show that,adding appropriate amount of water-repellent admixture,water reducing agent,early-strength admixture and fly ash can reduce the water absorption of air-foam treated lightweight soil,but the reduction effect is different.Adding 10% fly ash is most effective on reducing the water absorption of the air-foam treated lightweight soil,and it can reduce the water absorption by 4.8%. In addition,internal adding fly ash can not only decrease the water absorption rate of the air-foam treated lightweight soil,but also can replace cement to save cost to some extent,having better practicability in engineering application. After adding water reducing agent,the defoaming phenomenon is obvious,which leads to the significantly increased density of the air-foam treated lightweight soil,so the effect of water reducing agent on reducing the water absorption of air-foam treated lightweight soil is the worst. Although mixing appropriate amounts of water-repellent and early-strength admixtures can also reduce the water absorption of air-foam treated lightweight soil,the effect is not good,and due to the defoaming phenomenon caused by the compatibility issues,such measure lead to th
作者
杨卫东
黎冰
马文昊
YANG Weidong;LI Bing;MA Wenhao(School of Civil Engineering,Southeast University,Nanjing 210096,China)
出处
《防灾减灾工程学报》
CSCD
北大核心
2022年第5期1061-1068,共8页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目(51578145)资助。
关键词
气泡混合轻质土
吸水率
粉煤灰
憎水剂
减水剂
早强剂
air-foam treated lightweight soil
water absorption
fly ash
water-repellent admixture
water reducing agent
early-strength admixture
