离子土固化剂-水泥联合固化淤泥的微观机理研究

The disposal of large number of dredged silt in city area has become the problems of restricting the development of the urban economy and destructing environment. In order to alleviate the destruction of land resources and environment impact, and satisfy the demand of modern construction for great amount of earthwork material engineering, the study on dredged silt improvement has important theoretical significance and engineering application value. The research object is dredged silt in Wuhan city, which has high clay content and high organic content, the study methods and means include differential thermal analysis, X-ray diffraction experiment, electron microscope scanning, zeta potential test, specific surface area test, cation exchange test, matrix suction test, pore size distribution test, organic matter analysis and PH value determination test etc. The quantitative analysis is conducted on ionic soil stabilizer (ISS) influence on silt clay mineral adsorption weakly bound water, and the physical-chemical processes between the ISS and silt clay minerals are revealed, and the optimal proportion of the ISS and cement for silt solidification is to determine; Considering the process characteristics of organic matter, quantitative and qualitative analysis is used to examine the microstructure, mineral and percolating liquid composition, and the ISS composition is improved to reduce adsorption effect, which results from the organic and cement, influence on the delayed hydration process, by this way the microcosmic mechanism among ISS - cement - silt is to reveal for silt consolidation, the abovementioned study and findings provide important theory basis for dredged silt consolidation treatment and resource utilization.

疏浚淤泥的处置一直是困扰城市经济、环境发展的难题。为减少淤泥大量废弃堆置对土地资源的破坏及环境影响，满足工程建设对大量土方材料的需求，研究有效的疏浚淤泥改良利用具有重要的科学意义。本项目以高粘粒含量、高有机质含量的武汉疏浚淤泥为研究对象，采用差热分析、X射线衍射试验、电镜扫描、Zeta电位试验、比表面积试验、阳离子交换试验、基质吸力测试、孔径分布测试、有机质分析等综合试验手段，定量分析离子土固化剂（ISS）对淤泥粘土矿物吸附弱结合水的影响；结合有机质的作用特点，对其微观结构、矿物及渗出液化学成分进行定性和定量分析，以削弱有机质与水泥矿物间的吸附作用对水泥水化进程延缓的影响；研究ISS与淤泥中粘土矿物的物理化学作用过程，确定ISS-水泥联合固化淤泥的最优配比；揭示ISS-水泥-淤泥协同作用的微观固结机理，为疏浚淤泥固化处理及资源化利用提供理论依据。

为减少淤泥大量废弃堆置对土地资源的破坏及对环境的影响，同时满足工程建设对大量土方材料的需求，研究有效的淤泥改良方法具有重要科学意义和工程价值。. 本项目以武汉河漫滩相淤泥质土和福建宁德海相淤泥为研究对象，开展了离子土固化剂（ISS）、ISS-水泥、ISS-粉煤灰、水泥-生石灰-高铁酸钾-高分子吸水树脂（CCPS）复合固化剂分别固化淤泥的配方、制样方法、物理力学性质、微观性质的测试与试验数据处理，通过宏微观的定性和定量分析，研究了各固化剂组分对淤泥固化的物理化学作用过程；确定了各固化剂组分的最优配比；揭示了固化剂-淤泥的协同作用效应及微观固结机理；为淤泥固化处理及资源化利用提供了理论依据。. 取得的具体研究成果主要包括：研究了不同沉积相软土的工程特性；研制了固化淤泥的制样方法及配方，阐明了淤泥固化的协同效应及微观机理（包括ISS固化淤泥、ISS-水泥固化淤泥、ISS-粉煤灰固化淤泥、CCPS固化淤泥）。. 综上所述，本项目的研究成果对淤泥固化配方选择、固化剂作用机理、不同固化剂之间的相互抑制或协同作用原理、淤泥软土固化微观机理、污染土处理、土地资源环保等具有科学研究意义和工程应用价值。. 此外，研究成果具有工程实践应用前景，可应用领域如：废弃淤泥资源化利用、淤泥软土地基处理、污染土处置及再利用等。同时研究成果还具有一定的潜在国防应用前景，可解决行军过程中遇到淤泥、沼泽等软土环境时，在环保的基础上，进行软土的原地快速固化而形成硬壳层，提高地基承载力，解决人员和装备在承载力不足的软土环境中通行的问题。