A Review of Properties and Behavior of Sand-Clay Mixtures

The properties and engineering behavior of sand-clay mixtures has been the greatest concern among civil and geotechnical engineers in field of practice. The reason has been that, it is an important factor that should be put first because of the important properties of the mixture in the construction site. However, Sand-clay mixtures were not commonly found in its required proportion in nature and therefore rarely available for civil engineering projects unless by improvise method through a geotechnical engineer. The mixtures are prepared through the blending of clay and sand materials together with the required proportions by a geotechnical engineer. In this review, the general properties of the mixtures were discussed. Also the different categories of sands and clay materials available in the construction industries were itemized including their man-made/processed sources. The techniques applied in the preparation of different percentages of sand and clay in the mixtures was considered including the Sand gradation, chemical composition of the mixtures, clay mineralogy, compaction behavior, the CBR, effect of volume change and sand range on the volume change behavior. Finally their transitional behaviors as well as its application were looked into in order to enhance the full understanding of the properties with much emphasis on the engineering behavior of the mixture under discussion.砂-土混合料的工程特性与力学行为，始终是土木与岩土工程实践领域从业者最为关注的核心议题。究其原因，该混合料在施工现场具备关键工程特性，因此是土木工程项目中需优先考量的核心因素。然而，天然环境中极少存在符合工程所需配比的砂-土混合料，除非由岩土工程师通过人工配制手段制备，否则此类混合料难以直接供土木工程项目使用。岩土工程师需按照预设配比，将黏土与砂料均匀拌合，以此制备符合要求的砂-土混合料。本综述首先阐述了砂-土混合料的通用工程特性，随后逐一列明了建筑行业常用的各类砂与黏土材料，涵盖其天然与人工/加工来源。本次综述还探讨了不同配比砂-土混合料的制备工艺，涵盖砂级配、混合料化学成分、黏土矿物学、压实特性、加州承载比（California Bearing Ratio，CBR）、体积变化与含砂量范围对体积变形行为的影响。最后，本综述还分析了该混合料的过渡特性与工程应用场景，旨在全面深化对其工程特性的认知，尤其着重探讨了本文所讨论砂-土混合料的工程力学行为。