Types and amounts of fines affecting aggregate behaviour

摘要

Construction of a working platform is often needed on soft, unstable soils to provide suffi-cient stability and adequate support for equipment mobility and paving operations without developing excessiverutting. Subgrade removal and aggregate replacement for cover is one of the most commonly used optionsfor treating soft, unstable soils. Aggregate type and quality are important factors governing the required treat-ment/replacement thickness. This paper presents preliminary laboratory findings from an ongoing researchproject at the University of Illinois aimed to characterize behavior of three types of aggregates commonly usedin Illinois for subgrade replacement and subbase. Samples were prepared with consistent engineered gradations,and their moisture-density and strength behavior were studied at different amount of fines, as well as with differ-ent types of fines. Plastic fines were found to reduce aggregate strength significantly, as compared to the sameamount of non-plastic fines.