摘要
将绿色环保活性MgO-粉煤灰材料引入淤泥固化,采用系列室内模拟试验,深入研究冻融、浸水和干湿等复杂气候环境下活性MgO-粉煤灰固化淤泥试样的外观形貌和强度特征,明确外界环境干扰诱使固化淤泥性能演化的内在规律。结果表明:活性MgO-粉煤灰固化淤泥具有良好的抗冻融、抗干湿及水稳性,且活性MgO-粉煤灰掺量及MgO/粉煤灰配比提高可进一步改善活性MgO-粉煤灰固化淤泥试样的耐久性能。冻融、浸水和干湿等复杂环境显著劣化固化淤泥抗压强度,其强度水平均低于同龄期标准养护试样。固化淤泥试样无侧限抗压强度随冻融循环次数增加而逐渐降低,随浸水时间增加先降低后趋于稳定,随干湿循环次数增加呈降低的趋势。基于所得试验结果,提出了活性MgO-粉煤灰固化淤泥耐久性演变的内在微观机制模型。
Based on series of laboratory tests including cyclic freeze-thaw, water immersion and cyclic drying-wetting, an experimental study has been performed to analyze the intrinsic change in the compressive strength and appearance of dredged sludge solidified with reactive MgO-fly ash, a green and environmental-friendly binder, and clarify the climate change-induced durability evolution. The test results indicate that the dredged sludge solidified with reactive MgO-fly ash has outstanding performance in resisting the damage from cyclic freeze-thaw, water immersion and cyclic drying-wetting. The durability performance of reactive MgO-fly ash solidified sludge is significantly enhanced as the MgO-fly ash content and mass ratio of MgO to fly ash increase. The strength behavior of MgO-fly ash solidified sludge is largely weakened by water immersion, cyclic dry-wet and cyclic freeze-thaw, and this causes a smaller compressive strength than that of samples cured under standard condition. As the number of freeze-thaw cycle increases, the compressive strength tends to decrease gradually. The compressive strength of samples immersed in water is initially reduced, and then changes within a limited interval. The compressive strength of damaged samples decreases with the increasing drying-wetting cycles. Based on the test results, an intrinsic microscopic mechanism model is proposed for the durability evolution of dredged sludge solidified with reactive MgO-fly ash.
作者
王东星
王宏伟
邹维列
徐学勇
WANG Dong-xing;WANG Hong-wei;ZOU Wei-lie;XU Xue-yong(Hubei Key Laboratory of Safety for Geotechnical and Structural Engineering,School of Civil Engineering,Wuhan University,Wuhan,Hubei 430072,China;Hunan Provincial Key Laboratory of Hydropower Development Key Technology,Zhongnan Engineering Corporation Limited,Power China,Changsha,Hunan 410014,China;Dacheng Kechuang Foundation Construction Co.,Ltd.,Wuhan,Hubei 430021,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第12期4675-4684,共10页
Rock and Soil Mechanics
基金
国家自然科学基金（No.51879202,No.51609180）
武汉市科技计划项目（No.2018060402011257）
水能资源利用关键技术湖南省省重点实验室开放研究基金（No.PKLHD201701）~~
关键词
淤泥
活性MgO-粉煤灰
固化
抗压强度
耐久性
sludge
reactive MgO-fly ash
solidification
compressive strength
durability
