Compliance to construction and materials specification results into a pavement structure capable of carrying the design traffic within the design period. Therefore, there is need to establish feasible option of improving the available gravel economically and timely to meet the contractual specifications without financial and time related contractual implications.

Due to difficulties in getting natural gravel within project location that meets the required standard specifications for subbase layer construction, improvement of the available material mechanically to meet the required specifications is necessary. Thus it is necessary to carry out laboratory tests to identify the quantity of granular material to be used to minimise costs and ensure compliance to the specifications.