A CRITICAL STUDY ON USING FLY ASH IN NH PROJECT (KHARAR-LUDHIANA) AS AN EMBANKMENT FILL MATERIAL

Development projects such as highway construction in modern scenario requires a huge amount of earth material. The borrow earth required for this purpose is not available easily in and around the urban areas due to difficulties in getting borrow land from where the required amount of soil can be extracted as the space availability is one of the major issues in and around urban areas and the borrow land requires a lot of space for soil extraction. This results in increased cost of construction of the project especially those requiring a massive amount of soil such as highway projects. The solution for the above problem brings into the frame the use of mineral waste or by products as they are having a great potential to meet the growing demand and are also cost effective. Fly ash a waste by product obtained commonly from thermal power plants generally extracted by means of electrostatic/mechanical precipitator has been widely used in constructing highway embankments. Other than this it is also used in various other sectors such as cement manufacturing, brick making, mine filling, agricultural uses etc. One of the major reigons to bring fly ash in use in massive amount is to use it in embankment construction. This paper shows the results of both field and experimental investigation which was carried out to determine the suitability of using fly ash in a NH project as an embankment fill material and the cost which was incurred in constructing embankment by using fly ash .Fly ash effect on compaction of soil used was also evaluated. The experimental results obtained showed that the increased percentage of fly ash led to an increase in moisture content and a decrease in maximum dry density of soil used. The field compaction test showed the better compaction of fly ash bed achieved. The construction cost of NH embankment was also within acceptable limits of the project.