Highway engineering

Highways gained importance recent days due to the great advancement in vehicle manufacturing technology which helps to achieve very high speeds. But to maintain very high speeds, highways should be wide and damage free. Aggregate crushing value which gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load should be less for better results. A quantity which gives a measure of resistance to sudden impact or shock is termed as aggregate impact value which is very significant in the design of highways. Los Angeles test machine is a machine which measures resistance to abrasion of aggregate. For the determination of the abrasion value of road aggregates, we use Deval’s machine. For the determination of the strength of the subgrade soil for design of pavement thickness, California bearing ratio has to be calculated. For any Bituminous material, consistency test has to be carried out by a penetrometer and viscosity by a viscometer. A ring and ball apparatus can be used to determine softening point of Bituminous material.