For ‘T’
TACK
COAT: A thin coat of bitumen, road tar or emulsion laid on a road to
improve the adhesion of a course above it.
TANDEM
ROLLER: A road roller having rolls (drums) of about the same diameter
behind each other on the same track.
TACK
WELD: A temporary half-inch thick weld that holds steel parts together
during fabrication.
TEMPERATURE
STEEL: Reinforcement which is inserted in a slab or other concrete member
to prevent cracks due to shrinkage or temperature stresses from becoming too large.
It generally amounts to a minimum of about 0.1% of the cross-section in any
direction. The requirement for a slab, which is two-dimensional, being
therefore about 0.2% altogether.
TEMPERATURE
STRESS: A stress due to temperature rise or drop. If the expansion due to
temperature rise or the contraction due to temperature drop is restrained, the
member concerned is stressed in compression during rising temperature or
tension during falling temperature.
TENDON: A
pre-stressing bar, cable, rope, strand or wire.
TERZAGHI-MEYERHOFF
EQUATION: This equation is used to find the gross (ultimate) bearing
capacity or gross pressure for a soil:
THRUST: A
horizontal force, particularly the horizontal force exerted by retained earth.
TOPSOIL: The
topmost layer of the soil which by its humus content supports vegetation. It is
usually the top one foot of the soil.
TOLERANCE:
Acceptable variation from a standard size.
TOUGHNESS:
The resistance of a material to repeated bending and twisting.
TORQUE,
TORSION OR TWIST: The twisting effect of a force on a shaft applied tangentially,
like the twist on a haulage drum which winds rope on to its circumference.
TRAFFIC
LANE: That portion of a travelled way for the movement of a single line of
vehicles.
TRAVEL
LANE: When used to distinguish between passing lane and travel lane, the
travel lane is the right lane of a two lane roadway with both lanes going in
the same direction. Usually both the passing lane and the travel lane are
considered travel lanes with the passing lane considered to be the right travel
lane.
TRAVELED
WAY: The portion of the roadway for the movement of vehicles exclusive of shoulders
and auxiliary lanes.
TRUSS: A
frame, of steel, but also sometimes of timber, concrete, or light alloy, to
carry a roof or bridge, built up wholly from members in tension and
compression. It is generally a perfect frame or nearly so, and may be pin
jointed.
TURFING: The
covering of an earth surface with growing grass cut from another site. It can also
be revetment to slopes which are usually covered by water, made by laying
turves on the slope according to a technique like sliced block-work.
For ‘U’
UNIFORM
FLOW: Flow which has a constant depth, volume and shape along its course.
UPLIFT: (1)
An upward force on earth due to water leaking into a dam or from any point where
water is under high pressure. (2) Lifting of a structure caused by: frost
heave, or on the windward side by wind force, or in a dry climate by swelling
soil.
For ‘V’
VARRIED
FLOW: Flow that had a changing depth along the water course. The variation
is with respect to location, not time.
VIBRATED
CONCRETE: Concrete consolidated by vibration from an internal or external vibrator.
It requires very much less water for effective placing than does concrete
compacted by punning, therefore it is much stronger. The formwork, however,
must also be stronger when the concrete is to be vibrated. Concrete in
hollow-tile floors is not vibrated.
VIBRATOR:
A tool which vibrates at a speed form 3,000 to 10,000 rpm and is inserted
into wet concrete or applied to the formwork to compact the concrete.
For ‘W’
WARPING: Deviation
of pavement surface from original profile caused by temperature and moisture
differentials.
WATER FOR
DOMESTIC USE: Potable water used by the public (Home-use).
WORK: The
product of a force and the distance through which it moves. It is to be distinguished
from energy and from power which is a rate of doing work. Energy can, however,
be expressed in the same units as work, and often is.
WORK ON
ENGINEERING CONTRACTS: Work here shall mean the furnishing of all labor, materials,
equipment and other incidentals necessary or convenient to the successful completion
of the project and the carrying out of all the duties and the obligations
imposed by the contract.
WEEPHOLE:
A hole to allow water to escape from behind a retaining wall and thus to reduce
the pressure behind it.
WORKABILITY:
The ease with which a concrete can be mixed, placed and finished. Wet concretes
are workable but weak. Workability can be measured by the slump test, the compacting
factor test, and by the V.-B. Consist meter test.
For ‘X’
XYLEM: The
botanical name for wood.
For ‘Y’
YIELD OR
BUCKLE: The permanent deformation which a metal piece undergoes when it is stressed
beyond its elastic limit.
For ‘Z’
ZONING: Restrictions
as to size or character of buildings permitted within specific areas, as established
by urban authorities.