稻壳灰水泥固化淤泥土试验研究

为拓宽稻壳灰和淤泥土等固废资源处理途径,基于传统水泥固化处理方法,提出稻壳灰-水泥固化处理淤泥土技术。通过室内击实、无侧限抗压强度(UCS)和电镜扫描(SEM)试验,分析稻壳灰-水泥土强度特性及微观机理。结果表明:稻壳灰对淤泥固化土强度增强效果显著,并且15%稻壳灰+8%水泥掺量效果最佳,稻壳灰加入显著提高淤泥固化土韧性,其破坏应变在3%~5%左右,变形系数E₅₀与抗压强度近似呈线性递增关系,E₅₀可取(19~50)q_u。微观分析表明:水化硅酸钙生成是稻壳灰-水泥固化淤泥强度提高的主要来源,其填充孔隙、胶结作用使土体更加密实,提高强度。基于试验结果,提出了稻壳灰-水泥固化淤泥微观演变机制分析模型。

Experimental Study of Sludge Solidification with Adding Rice Husk Ash and Cement

In order to expand the treatment of solid waste resources such as rice husk ash and sludge, a new solidification method by adding rice husk ash (RHA)-cement is proposed based on traditional cement treatment method. By compaction, unconfined compressive strength (UCS) test and scanning electron microscope (SEM), the strength characteristics and micro mechanism of RHA-cement soil were analyzed. The test results show that: RHA has a significant effect on the strength of stabilized sludge, and there is an optimal dosage of 15% RHA + 8% cement.Adding RHA can greathy improve the toughness of sludge, and the failure strain is about 3%~5%. The relationship between deformation coefficient E₅₀ and UCS is approximately linear increasing, E₅₀ can be taken as (19~50) q_u. Micro analysis shows that: The formation of hydrated calcium silicate is the main source of the strength improvement of RHA-cement soil, its pore filling and cementation make sludge more compact and strength improved. Based on the experimental results, the internal micro mechanism model of RHA-cement soil was proposed.