Construction of roads involves the paving, rehabilitation, and/or reclamation of degraded pavements in order to achieve a state of good repair and increase road traffic safety. Road construction involves the use of asphalt, liquid asphalt, concrete, soil stabilization, rebar, paving and pavement recycling machines, and other road repair materials.
A wide variety of materials are used in the construction of roads these are soils (naturally occurring or processed), aggregates (fine aggregates or coarse aggregates obtained from rocks), binders like lime, bituminous materials, and cement, and miscellaneous materials used as admixtures for improved performance of roads under heavy loads and traffic.
Soil constitutes the primary material for the foundation, subgrade, or even the pavement (for low-cost roads with low traffic in rural areas). When the highway is constructed on an embankment at the desired level, soil constitutes the primary embankment material; further, since all structures have to ultimately rest on and transmit loads to ‘mother earth’, soil and rock also serve as foundation materials.