AGGREGATE Crushed rock or gravel, screened to
sizes for use in road surfaces, concrete, or
ANGLING DOZER (Angledozer)A bulldozer with a
blade that can be pivoted on a vertical center pin so
as to cast its load to either side.
APRON The front gate of a scraper body.
ASPHALT A dark brown to black cementitious
material in which the predominating constituents
are bitumens that occur in nature or are obtained in
petroleum processing. Asphalt is a constituent in
varying proportions of most crude petroleums.
ASPHALT CEMENT A fluxed or unfluxed asphalt
specially prepared as to quality and consistency for
direct use in the manufacture of asphalt pavements.
ASPHALT CONCRETE High-quality thoroughly
controlled hot mixture of asphalt cement and
well-graded, high-quality aggregate, thoroughly
compacted into a uniform, dense mass.
ASPHALT LEVELING COURSE A course (asphalt
aggregate mixture) of variable thickness used to
eliminate irregularities in the contour of an existing
surface before a superimposed treatment or
ASPHALT, MEDIUM-CURING (MC) Cutback
asphalt, composed of asphalt cement and a kerosene
type of diluent of medium volatility.
ASPHALT, RAPID-CURING (RC) Cutback asphalt,
composed of asphalt cement and naphtha or
gasoline type of diluent of high volatility.
ASPHALT, SLOW-CURING (SC) Cutback asphalt,
composed of asphalt cement and oils of low
AUGER A rotating drill having a screw thread that
carries cuttings away from the face.
AUXILIARY A helper or standby engine or unit.
AXIS OF ROTATION The vertical line around which
the upper structure rotates.
AXLE, LIVE A revolving horizontal shaft.
BACKFILL (1) The material used in refilling a ditch
or other excavation. (2) The process of such
BAIL BLOCK Block attached to a dragline bucket,
through which rope line is reeved. Also referred to
BAIL (BUCKET) A yoke or spreader, hinged to the
sides of a dragline bucket, to which is attached a
connecting sheave or chain for hoisting and
BALL JOINT A connection, consisting of a ball and
socket, that will allow a limited hinge movement in
BANK Specifically, a mass of soil rising above a
digging or trucking level. Generally, any soil that is
to be dug from its natural position.
BANK GRAVEL Gravel found in natural deposits,
usually more or less intermixed with fine material,
such as sand or clay, and combinations thereof;
gravelly clay, gravelly sand, clayey gravel, and
sandy gravel indicate the varying proportions of the
materials in the mixture.
BASE COURSE The layer of material immediately
beneath the surface or intermediate course. It may
be composed of crushed stone, crushed slag,
crushed or uncrushed gravel and sand, or
combinations of these materials. It also may be
bound with asphalt.
BANK YARDS Yards of soil or rock measured in its
original position (before digging).
BEDROCK Solid rock, as distinguished from
BENCH A working level or step in a cut that is made
in several layers.
BINDER (1) Fines which hold gravel together when it
is dry. (2) A deposit check that makes a contract
BITUMEN A class of black or dark-colored (solid,
semisolid, or viscous) cementitious substance,
natural or manufactured, composed principally of