Keywords of Road Pavements:
Pavement : That part of a road which structurally supports the vehicles travelling on a road.
Flexible Pavement : A layered system of pavement withstanding wheel loads by lateral distribution.
Rigid Pavement : A cement concrete pavement having a slab of high strength and withstanding external loads by beam action.
Wearing Surface : The topmost layer in a flexible pavement.
Base Course : The layer immediately below the wearing surface in a bituminous course.
Granular Sub-base (GSB) : The bottom-most layer of a flexible pavement that rests on the sub-grade.
Sub-grade : The top portion of the soil embankment that supports the pavement.
Drainage Layer : The bottom-most layer of a pavement (flexible or rigid) that serves to drain away the water entering through the pavement layers.
Borrow Pits : Pits dug to borrow earth for embankment construction.
Damaging Power : The damage on overloaded axle causes to a pavement as compared to a standard axle load.
Vehicle Damage Factor (VDF) : The damage caused to a pavement by each commercial vehicle.
Load Distribution Factor : The traffic to be considered in the design lane as a fraction of the full traffic in both directions.
Design Period : The number of years for which a pavement is designed.
Traffic Growth Rate : The rate at which traffic grows every year over the design period.
Million Standard Axles (msa) : The repetitions of the standard axle load in millions over the design period.
Soil Stabilisation : Process of treating a soil to improve its properties.
Mechanical Stabilisation : Blending soil with better materials to obtain a better particle size distribution.
Chemical Stabilisation : Addition of additives like lime, cement, lime- flyash, bituminous materials to soil to improve its properties.
Brick Pavement : Pavement using full bricks laid flat or on edge.
Over-burnt Brick Ballast : Aggregates formed by breaking over-burnt (Jhama Metal) bricks.
Stone Soling : A pavement layer using stone boulders.
Water Bound Macadam : A pavement layer with aggregates held together by a film of screenings and binding material in the pressure of water.
Wet Mix Macadam : A layer of graded aggregates mixed with water in a plant and laid by a paver.