Compaction characteristics of lateritic soil mixed with fly ash and lime

The compaction characteristics of a lateritic soil modified with a low-calcium fly ash and lime was investigated in the laboratory. The maximum amount of soil replaced with fly ash was limited to 50%. Lime was added in quantities varying from 2% to 4% of the dry weight of soil-fly ash mix. Moisture-dry unit weight relationships were determined for the mixes by using a fresh specimen for each point even after a delay period extending up to 3 days. Fresh specimens were also subjected further to three re-compaction cycles without any delay. The test results indicate that the addition of both fly ash and lime cause immediate reduction in the maximum dry unit weight. Compaction delay leads to a further decrease only for mixes containing lime. However, there is an increase in maximum dry unit weight after re-compaction of the soil-fly ash mixes, and the effect is more pronounced for mixes with lime added.