冰冻作用对固化污泥强度及变形特性影响

冻融作用会引起固化污泥的破坏,威胁工程体的稳定性。本文在封闭系统下,对固化污泥进行冻融试验,研究了不同冰冻发生时间及不同冻结时间对固化污泥抗压强度及变形特性的影响,并根据试验结果选取试样进行电镜扫描。研究结果表明:冻融作用对固化污泥的强度及变形特性影响很大,且源于冻融作用对固化污泥微观结构的影响;冰冻发生时间越早,水化程度越低,颗粒粘结越弱,固化体整体性越差,强度越低,冻融作用引起的强度衰减越大,固化体呈现塑性破坏;冰冻时间越长,引起的强度破坏越大,但强度衰减率随时间增加较小。上述研究成果可为寒区污泥固化填埋的安全处理提供技术参数及指导。

Study of the Influence of Freezing and Thawing on Strength and Deformation Properties of Solidified Sewage Sludge

Freezing and thawing action(FTA) can cause destruction of solidified sludge and threaten the stability of engineering body. Solidified sludge freezing and thawing experiment was conducted in a closed system. The influence of different freezing occurrence time and different freezing duration time on the compression strength and deformation characteristics of solidified sludge was studied and scanning electron microscope (SEM) detection was also conducted for selected samples from experimental results. Results show that the influence of freezing and thawing action on the strength and deformation properties of solidified sludge is very obvious due to FTA changes the microscopic structure of solidified sludge. The earlier the freezing occurrence time is, the lower the hydration degree, and the weaker the particle bonding, and the worse the integrity of solidified body, and the lower the strength, and the larger the strength attenuation is, and the solidified body presents plastic destruction; the longer freezing duration time is, the greater the strength damage caused, but the less of increase of strength attenuation. Above results may provide parameters and guiding for safely landfilling of solidified sludge in cold regions.