Compressibility of Kaolinitic Clay Contaminated by Ethanol-Gasoline Blends

In this work, oedometer tests were used to examine the effects of ethanol-gasoline blends on the consolidation characteristics of a kaolinitic soil from northwestern Spain. As the fraction of ethanol in blends increases, the equivalent liquid limit of soil decreases, showing a dividing point for blends containing about 85% of ethanol. By means of a database of compression indexes of remolded clayey soils mixed with differing kinds of alcohol and petroleum hydrocarbon contaminants, a multivariable model for estimating the compression index of the contaminated soil is presented, on the basis of the virgin compression index, normalized liquid limit, and normalized pore fluid viscosity. The model is valid only for percentages of active clays up to 10-15% in weight in kaolinitic soil. The authors would like to encourage others to further validate and refine the approach, which may be useful for preliminary estimation of the compression index of contaminated soils, reducing operators' risk of inhaling vapors released by the ethanol-gasoline blends while performing the test and also reducing damage to conventional oedometer equipment. DOI: 10.1061/(ASCE)GT.1943-5606.0000494. (C) 2011 American Society of Civil Engineers.