INTRODUCTION A huge amount of investments are used for maintenance, construction and extending roads and freeways in many countries. Statistics shows that during last fifty years, the most investments are used on roads in compare to other general infrastructures (1). The roads built with conventional methods do not satisfy the huge volume of loads no more. However, in undeveloped and developing countries such as Afghanistan, which are many limitations (e.g., limited time schedule because of internal civil war, lack of good quality material, over loading passing trucks and budget), the conventional methods may be cost and execution time effective. Thus, new methods must be adopted for new roads to increase the bearing capacity of the pavements. The concept of soil modification through stabilization with additives has been around for several thousand years (2). Even today, stabilization with manufactured additives such as lime, lime fly ash, Portland cement, bituminous materials, fibers and geo-synthetics are gaining popularity in many parts of the world (3). Attention has been focused on substitute materials such as stabilized soils.