STUDY ON THE DEVELOPMENT OF THE MUDDY SOIL HARDENING TREATMENT BY INDUSTRIAL WASTES AND THE EFFECTIVE USE OF THE TREATED SOILS

建筑工地产生的淤泥质土（如Hedoro）数量不断增加，其中一些已被用作建筑材料。然而，1990年我国每年产生的未利用建筑垃圾量为7600万t，其中约20%为受污染的污泥。各种工业废料也有同样的问题。从保护自然资源和减轻环境影响的角度来看，土壤和废弃物的再利用是非常重要的，本研究的目的是改善含水量和有机质含量高的淤泥质土壤的通过性或土方移动性，并提高其强度。为了实现这些目标，硬化剂波特兰水泥和外加剂被添加到淤泥质土，和他们的效果进行了研究。采用三种工业废料（混凝土粉、造纸污泥灰和粉煤灰）和一种天然材料（颗粒膨润土）作为外加剂，研究了它们的掺合料性能，结果表明：（1）它们的掺合料比膨润土的掺合料具有更好的抗裂性能; ...更多信息 清楚地表明，通过将所使用的每种外加剂添加到淤泥土中，处理土的强度得到增强，并且证实存在外加剂和土的理想混合比。(2)混凝土粉和造纸污泥灰是有机质含量低、含水量低的淤泥质土的有效掺合料。例如，与造纸污泥灰混合的处理过的土壤比仅混合水泥的强度增加2-3倍。(3)可乐粉煤灰获得了最大的硬化效果，由于在所有处理过的土壤中钙矾石的生产。含有SO_3离子和火山灰物质的粉煤灰混合处理后的土壤强度是造纸污泥灰混合处理后的强度的两倍。因此，粉煤灰可以被认为是“最合适的掺合料”。(4)膨润土在一定程度上受到水分含量降低和内聚力增加的影响。(5)如果使用这些掺合料，则可以减少硬化剂的用量，并在强度达到预期水平时缩短养护时间。(6)当土用特殊混合水泥处理时，从早期养护龄期到长期养护龄期都可以观察到高的硬化强度。(7)有助于强度的硬化反应产物是CSH基团反应产物和钙钒石晶体。(8)强度低到可以进行无侧限抗压试验的程度，可以通过落锥试验来估算。因此，可以预测长期的团队强度，并利用该测试的结果对处理过的土壤进行质量控制。少

The amount of muddy soil such as hedoro from construction sites has been increasing, and some of them has been used as contruction material. However, the annual amount of unused construction waste was 76,000,000t in 1990, and about 20% of it was polluted sludge. Various inductrial wastes also have the same problem. It is very important to reuse the soil and waste, from the viewpoint of natural resource preservation and environmental impact mitigation.The purpose of this study is to improve the trafficability or earth-moving property and to increase the strength of muddy soil which is high in water content and organic matter. In order to achieve these objectives, a hardening agent Portland cement and the admixture were added to the muddy soil, and their effects investigated. The used admixtures are three types of industrial waste (concrete powder, paper sludge ash and coal fly ash), and one natural material (granular bentonite).The obtained results are summarized as follows :(1) It is m … More ade clear that the strength of the treated soil is enhanced with the addition of each of the used admixtures to the muddy soil, and it is confirmed that an ideal mixing ratio of admixtures and soil exists.(2) Concrete powder and paper sludge ash are effective as admixtures to muddy soil with less organic matter and low water content. For instance, the treated soil mixed with paper sludge ash became 2-3 times stronger compared with that only mixed cement.(3) Cola fly ash obtained the greatest hardening effective due to the production of ettringite in all treated soils. The strength of the treated soil mixed with the coal fly ash which contained SO_3 ion and pozzolanic material was twice that of the paper sludge ash mixing. Therefore, the coal fly ash can be considered "most suitable admixture".(4) Bentonite is affected to some degree by a reduction in moisture content and increased cohesion.(5) If these admixtures are used, it is possible to decrease the quantity of hardening agent used and to reduce the curing period when the strength achieves the expected level.(6) When the soil is treated with the special-blended cement, the high hardening strength can be observed from the early curing age through the long term.(7) The hardening reaction products which contribute to a strength are CSH group reaction products and ettringite crystals.(8) The strength, which is so low that the unconfined compression test can be performed, can be estimated by the fall cone test. It is consequently possible to predict the long team strength and to utilize the results of this test for a quality control of the treated soil. Less