碱性材料与红土坝料的互损劣化试验

Deterioration reaction between alkali materials and laterite dams

水泥、石灰等碱性物质被大量用于加固土工结构,然而碱性材料已经给红土造成了长期的侵蚀。基于材料互损的化学分析,设计了红土坝料的加速劣化浸泡,对比试验了水工指标,分析了渗水的离子浓度变化。检测证实:碱性物质降低了倍半氧化物的聚合力、消耗了红土的黏结成分、劣化了结构材料的颗粒级配。揭示了碱性加固材料与酸性坝土的相互作用及接触带互损渗漏机制,提出材料互损是导致土坝重要指标逐渐劣化、细观渗流通道增加扩大、加固效益太低的重要原因之一。

Alkali substances, such as cement and lime, have been largely used to reinforce soil structure. But the laterite has been chronically eroded by alkali materials. Based on the chemical analysis of mutual deterioration of the materials, accelerated life dip in calcium hydroxide is designed for the laterite. The hydraulic factors are compared and the ion concentrations of seepage are tested. The test results show that the alkali substances reduce the cohesion of sesquioxides, depletes the clay particles of the laterite, and leads to poor-gradation of soil. Mutual deterioration of alkali reinforcement materials and acidic laterite is released. The leakage mechanism of contact zone is found for the acid and alkali materials. It is helpful for the strengthening of laterite dams.