长江沿线水泥系阻隔墙材料长期工作性能劣化研究

Study on long-term working performance deterioration of cement barrier wall materials along the Yangtze River

长江中下游分布着众多化工企业,近年来沿岸各地陆续进行化工企业搬迁,关停并转留大量重金属污染场地,对周围环境和水体形成威胁。竖向隔离墙是一种经济有效的阻控污染物水平运移的工程措施,目前针对水泥系竖向阻隔墙材料配比、吸附性能和渗透特性已开展部分研究工作,但对其在污染场地的长期工作性能的研究较少。文章通过室内试验研究典型水泥系阻隔墙材料在重金属溶液浸泡和重金属+干湿循环作用下的劣化特性,通过外观、质量损失率和无侧限抗压强度等指标分析水泥系阻隔墙材料在重金属污染场地的长期工作性能。研究结果表明:水泥系阻隔墙对单一重金属侵蚀具有较好的耐久性,但在重金属溶液浸泡和干湿循环耦合作用时,水泥系阻隔墙材料的强度会发生一定程度的劣化,需重点关注该工况下,水泥系阻隔墙材料的长期耐久性能。

There are many chemical enterprises in the middle and lower reaches of the Yangtze River.In recent years,chemical enterprises have been relocated and shut down,leaving heavy metal polluted sites,which pose threat to the surrounding environment and water.Vertical barrier wall is an economical and effective engineering measure to prevent and control the horizontal migration of pollutants.At present,some studies have been carried out on the material ratio,adsorption properties and permeability characteristics of cement vertical barrier wall,but there are few reports on its long-term working performance in contaminated sites.In this paper,the deterioration characteristics of typical cement barrier wall materials under heavy metal solution immersion and dry wet cycling were studied through laboratory experiments,and the long-term performance of cement barrier wall materials in heavy metal contaminated sites was analyzed through indicators such as appearance,mass loss rate and unconfined compressive strength.The test results show that cement barrier wall has good durability against single heavy metal erosion.However,the strength of the cement barrier wall material will deteriorate to a certain extent when the heavy metal solution is soaked and the dry-wet cycle is coupled.Attention should be paid to the long-term durability performance of cement-based partition wall materials under this operating condition.