Laboratory evaluation of fly ash treated embankment and base materials : final report.

PDFTech ReportResearch Report No. 204Research Project No. 83-1SFly ashEmbankmentsLaboratory testsBase course (Pavements)Soil stabilizationHydraulic cementCalcium hydroxideAlternatives analysisLouisianaLouisiana. Department of Highways. Research and Development SectionMcManis, K.Louisiana. Department of Highways. Research and Development SectionUnited States. Federal Highway AdministrationUS Transportation CollectionThis study was undertaken to provide the Louisiana DOTD with a data base from which recommendations can be made concerning the modification or stabilization of soils using a Class C fly ash as a full or partial replacement for hydraulic cement or hydrated lime. It includes test data from two road base soils that are used in embankment construction. The test specimens were combined with lime, cement, and/or fly ash from three generating plants in Louisiana.The base soils consisted of an A-3 sand and an A-2-4 sandy-silt. Unconfined compressive and vacuum saturation strengths were compared to those presently required for stabilization using cement as a single additive. The test results indicate the importance of the characteristics of the gradation of the materials and the effects of the presence of fines in the soil.Two clays, an A-6(9) and an A-8-6(20), were evaluated by comparing the improvements in the plastic properties and the gain in soil support with the addition of fly ash and/or lime. The amount of free lime present in the Class C fly ashes tested was insufficient to effectively compete with lime alone in modifying the plasticity of the clays. The fly ash did enhance the soil\ue2\u20ac\u2122s resistance or R-Value when combined with lime