CORRELATION ANALYSIS OF LABORATORY COMPACTION OF FLY ASHES

Fly ash, a waste from thermal power stations, has been used in many countries to build highway embankments, fills, landfill liners, and covers. The maximum dry density (MDD) and optimum moisture content (OMC) of fly ash or fly ash-soil mixtures are determined by conducting compaction test. There is a large variation in the MDD and OMC of different fly ashes due to the differences in thencharacteristics. In the present study, data regarding the compaction characteristics and specific gravity (G) of different fly ashes were collected. Correlation analyses of the data for 57 samples for light (standard Proctor) compaction and 21 samples for heavy (modified Proctor) compaction were carried exit. Correlations have been developed for MDD and OMC for both light and heavy compaction. The correlation for MDD in terms of OMC and G and that between MDD and OMC have been expressed in the form of log-log, exponential, and linear curves. The general applicability of the correlations for light compaction has been tested with the data of 19 additional samples that were not used in establishing the correlations. The correlations between MDD and G, and between OMC and G. can be used to make a preliminary estimate of the likely range of MDD and OMC if the specific gravity of fly ash is known. This will be useful for the efficient design of the compaction test and for field compaction control in sites where establishing sitespecific correlations is expensive and time consuming.