不同工况条件混合赤泥力学特性变化规律

在利用常规土工实验和XRF、XRD、SEM等微观测试手段分析了刚出厂混合赤泥化学成分、矿物组成、微观结构的基础上,通过无侧限抗压强度实验和固结排水三轴剪切实验对自然风干、浸水饱和、非饱和-饱和干湿循环3种工况条件下混合赤泥不同龄期力学特性的变化规律进行了研究。结果表明,自然风干试样的无侧限抗压强度和粘聚力要明显大于相同龄期浸水饱和试样和干湿循环试样,说明混合赤泥的强度形成与滤水过程有一定联系,且其强度的增长均主要集中在脱水龄期前70天内;混合赤泥在3种不同工况条件下无侧限抗压强度和粘聚力均有一定程度的增长,说明混合赤泥可在浸水环境下生成不可逆增长的具有水硬性的胶结矿物,使其在水环境中不发生崩解,可保证混合赤泥堆体在自然堆存过程中其力学特性满足安全堆载要求。

Change rules of mechanical properties of red mud from mixing process under different working conditions

The chemical component, mineral composition and microstructure of fresh mixed red mud were studied by routine soil test and microcosmic measures such as XRF, XRD, SEM etc. On that basis, different mechanics features of red mud at three different ages were studied by unconfined compression strength test and triaxial consolidation drained shear test. Three working conditions were natural withering, immersed water saturation and unsaturated-saturated dry-wet cycle. From the results, we can find that the unconfined compression strength and cohesion of natural withering samples are obvious greater than the immersed water saturated and dry-wet cycle samples at the same age, thus there are some connections between strength formation and filtering process. The rising of unconfined compression strength and cohesion concentrate on the first 70 days of dehydration age. The red mud's unconfined compression strength and cohesion under three conditions have a certain growth, which can prove that they generate irreversible growth cementing mineral with hydraulic. The cementing mineral makes the disintegration of red mud disappear in water, therefore, the mixed red mud can make the mechanical feature meet the demand of stack and transportation.