碱-土激发反应对淤泥固化效应的热力学模拟与调控方法

本项目面向我国水库清淤工作对高效率资源化利用水库底淤（库淤）的需求，聚焦基于水泥土技术实现库淤资源化过程中，在应对高分异性库淤时，由于目前学术界对水泥土中碱激发土壤矿物（碱-土激发）反应机理的认识有限，导致库淤资源难以高效利用以及性能调控的难题。对此，首先引入热力学模拟法，构建变化原材料下水泥土矿物成分及孔隙率演变的预测模型；此后根据预测结果及库淤矿相，采用商用矿物制备人工水泥土，通过X射线全谱拟合法和压汞分析的定量结果优化初始模型；根据抗压强度、矿物过饱和度、Si核磁谱的经时演化特征，探明原材料、碱-土激发反应及水泥土强度间的交互作用机制；最终预设调控目标，修正库淤有机质含量、颗粒分布产生的预测偏差，构建高效、可靠的基于热力学模拟调控固化库淤性能的方法。研究成果将拓展热力学模拟在水泥土的应用，在丰富水泥土的理论体系与分析技术方面具有科学意义，对促进我国水库清淤增效具有重要应用价值。

This program aims at the national demands for efficient re-utilization of reservoir sludge in reservoir dredging in China by focusing on the issue of the unstable strength performance of the stabilized sludge in applying the cement stabilization techniques to deal with the reservoir sludge of high variability. The issue is due to the fact that the knowledge of the mechanisms of the alkali-activation of soil minerals in the cement-stabilized soils is limited.. First of all, the thermodynamic modelling of the system of cement-stabilized soil was introduced to establish an initial model of predicting the mineralogy and porosity of the stabilized sludge under the condition of changing raw materials. Then, based on the predictions and sludge mineralogy, artificially stabilized sludge specimens were prepared, and the initial model was optimized by the results of XRD-Rietveld analysis and mercury intrusion porosity. The interaction mechanisms between the raw materials, alkali-soil activation, and the stabilized sludge strength were clarified by analyzing the time-dependent behaviors of compressive strength, mineral supersaturation degree, and Si NMR spectroscopy. Hereafter, the regulation goals were predefined, the prediction deviations originated from the organic matter content and particle size distribution of the sludge were corrected, and the regulation approaches to the compressive strength of the cement-stabilized sludge of high reliability and efficiency based on the thermodynamic modelling were established. The research findings will extrapolate the application of thermodynamic modelling to the system of cement-stabilized soil, enrich the theoretical system and analyzing technology of the cement-stabilized soil, and promote the reservoir dredging efficiency in China.