The physical, chemical, and engineering properties that are likely to affect the use of bottom ash as a highway material were assessed. Laboratory studies conducted on indiana bottom ashes included three phases: ash characterization tests, engineering property tests, and environmental evaluation. Ash characterization tests consisted of physical appearance observation, chemical composition analysis, specific gravity determination, and gradation analysis. Engineering property tests included the testing of durabilty, abrasion resistance, maximum and minimum void ratio, permeability, compaction, degradation, shear strength, compressibility, and california bearing ratio. The test results are compared with representative values obtained fortypical granular soils. The environmental evaluation shows that bottom ashes have a nonhazardous nature, minimal effects on ground water quality, low radioactivity, and low erosion potential, but they may be potentially corrosive. In conclusion, with favorable engineering properties and minimal adverse environmental effects (except for corrosiveness), untreated bottom ashes can be extensively used in highway construction, such as embankments, subgrades, subbases, and even bases. However, those bottom ashes having high corrosiveness should not be placed in the vicinity of any metal structure. This paper appears in transportation research record no. 1310, Construction innovations 1991.
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