Basic Keywords related to road materials:
Sub-grade : The portion of road embankment immediately below the pavement.
Soil Classifications : A system of classifying soils.
Gravel : A coarse gained soil having more than half of coarse fraction.
Sand : A coarse gained soil having less than half of coarse fraction.
Slit : A fine grained soil having particles of size 0.002- 0.075 mm.
Clay : A fine grained soil having particles of size less than 0.002 mm.
Soil Compaction : Densification of soil to a desired density.
Optimum Moisture Content : The moisture content at which the density is (OPM) maximum.
Maximum Dry Density (MDD) : The maximum density of soil achieved with optimum moisture content.
Proctor Density : Density obtained by the method of compaction prescribed by Proctor and used for low volume roads.
Modified AASHTO Density : Density obtained by a heavy rammer and used for high traffic roads.
Sand Replacement Method : A method of determining the density achieved in the field.
Califormic Bearing Ratio : A measure of the supporting capacity of a soil (CBR) sub-grade.
Igneous Rocks : Rocks such as granite and basalt formed by cooling of molten volcanic material.
Sedimentary Rocks : Rocks formed by deposition of granular material.
Metamorphic Rocks : Rocks formed by transformation of igneous and sedimentary rock through heat and pressure.
Limestone : Rock containing mainly Calcium Carbonate.
Laterite : Rock formed by decomposition of basalt and other rocks.
Gradation : A system of determining the particle size distribution of aggregates.
Deleterious Material : Materials like vegetable matter, soft particles, clay lumps, mica, coal, etc. which can adversely affect the performance of road aggregates.