Due to non-availability of uniform strength of the soil, it needs to be modified either mechanically or by using additives so that pavement is supposed to provide adequate strength in terms of California bearing ratio (CBR).These days there is an increase in usage of bio enzymes to stabilize soil.
As pavements are designed to distribute stresses imposed by traffic to the subgrade, the subgrade conditions play a significant influence on the choice and thickness of pavement structure.
A proper understanding of subgrade material in pavement section is essential for engineer to construction, rehabilitation, or widening of a highway facility.
