HP Bitumen Handbook - Hindustan Petroleum Corporation Limited

Appendix-I : road metals and
materials
The load acting on the piston is recorded and that corresponding to a penetration
of 2.5mm is determined. The ratio of that load to 1360 kg (The value obtained
from a standard crushed stone sample) expressed as percentage is the CBR
value of this material.
CARPET - The term is applied to the wearing surface topping or top course of a
bituminous surface laid in two or more coats.
CHIPS - Small angular fragments of stone containing no dust.
CHOKE - To fill up the voids.
CINDER -
Slag particularly from iron blast furnaces or the accumulation of
clinkers, ashes and cinders resulting from burning coal.
CLAY - A type of soil which contain colloidal scale-like particles which are the
cause of plasticity. Plasticity and dry strength are affected by shape and mineral
composition of the particles.
COHESION - The force that binds the particles of any material together.
CORRUGATIONS - Ripples, waves or unfirm undulations which are liable to
appear in all types of road surfaces.
COURSE - One or more layers of road metal spread and compacted separately
for the formation of the road or pavement. Courses are often referred to in the
order of their laying, as first course, second course, third course, etc.
CROWN - The higher part of the curved surface of the road. Often used to
designate the difference in elevation of the highest point of a roadway and the
edge of the traveled way. Also the highest point on a cross-section, within the
traveled way, usually at the centre.
CRUSHED GRAVEL - Crushed gravel is considered suitable for use in
bituminous mixtures if at least 95% of the particles have one fractured face due
to crushing.
CRUSHED ROCK - Crushed rock is obtained by mechanically crushing quarry
stone, gravel or talus.
31