有机质和固化材料对固化污泥回填材料性能的影响与机理

Effect and Mechanism of Organic Matter and Solidification Materials on Performance of Solidified Sludge Backfill Materials

摘要:

通过开展无侧限抗压强度、物相组成、微观形貌分析和重金属含量测定等试验，研究了有机质含量和固化材料类型对固化污泥回填材料性能的影响与机理。结果表明：有机质对水泥和污泥固化剂的固化效果均有显著抑制作用；污泥固化剂固化污泥7、28 d无侧限抗压强度分别为水泥固化污泥的3.0~4.2、3.1~4.5倍；与水泥固化污泥相比，污泥固化剂固化污泥生成了更多钙矾石晶体，其对污泥颗粒间隙挤密填充，并结合水化硅酸钙凝胶对污泥颗粒的胶结作用，显著提高了固化污泥的密实度，且对污泥中重金属的稳定效果更佳；固化污泥作为路基回填材料，强度满足规范要求，污染风险低。

Abstract:

Through experiments such as unconfined compressive strength tests， phase composition and microstructure analysis， and heavy metal content determination， the effect and mechanism of organic matter content and the type of solidification materials on the performance of solidified sludge backfill materials were investigated. The results show that organic matter has a significant inhibitory effect on the solidification effects of cement and sludge solidifier. The unconfined compressive strength of sludge solidifier solidified sludge at 7 days and 28 days are 3.0-4.2 times and 3.1-4.5 times that of cement solidified sludge. Compared with the cement solidified sludge， the sludge solidifier solidified sludge generates more ettringite crystals， which compactly fill the gaps between sludge particles. Combined with the cementing effect of calcium silicate hydrate gel on sludge particles， the compactness of the solidified sludge is significantly improved， and a better stabilization effect on the heavy metals in sludge is demonstrated. The strength of the solidified sludge as a subgrade backfill material meets the requirements of the specification， and the pollution risk is low.