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©
Canadian Standards Association
Precast concrete — Materials and construction
November 2009
Camber
—
(a) the upward deflection caused by prestressing (does not include dimensional inaccuracies); and
(b) a built-in upward curvature to compensate for anticipated deflection.
Clearance
— interface space (distance) between two elements.
Note:
Clearance is normally specified to allow for the effects of product and erection tolerances and for anticipated
movement (e.g., deflection, thermal movement).
Concrete cover
— the distance from the concrete surface to the nearest deformation (or surface for
smooth bars or wires) of the reinforcement.
Connection
— a device for attachment of precast concrete elements to each other or to a building
structure.
Construction joint
— a surface where two successive placements of concrete join.
Corrosion inhibitor
— a chemical added to concrete to delay the onset and reduce the rate of corrosion
of reinforcement by chlorides by chemically influencing the kinetics of the electrochemical corrosion
reaction at the reinforcement surface.
Note:
See Annex C in CSA S413 for information on corrosion inhibitors.
Creep
— a time-dependent deformation under sustained stress.
Note:
In some cases, creep is also known as plastic flow.
Curing
— the maintenance of the humidity and temperature of freshly placed concrete during a definite
period following placing, casting, or finishing to ensure satisfactory hydration of the cementitious
materials.
Note:
When the curing temperature remains in the normal environmental range (generally between
10
and
30 °C
), this
Standard uses the term “normal curing”. When the curing temperature is increased to a higher range, this Standard uses the
term “accelerated curing”.
Debonded tendon
— a stressed tendon that is permanently prevented from bonding to the concrete in
the end zone.
Note:
This is achieved by use of a bond breaker or ducts.
Detensioning of tendon
or
wire
— the transfer of tension from the bed anchorage to the concrete.
Differential camber
— the difference in elevation between slabs of identical size, length, and
prestressing force.
Documented
— written technical substantiation of the use of a particular material, design practice, or
construction method that satisfies the intent of this Standard.
Draft
— the slope of a concrete surface in relation to the direction in which the precast element is
withdrawn from the form.
Note:
Draft is provided to facilitate stripping with a minimum of form breakdown.
Draped tendon
— a tendon that is held up at specific points and held down at others to form a desired
profile.
Note:
This practice can be referred to as harping, deflecting, or depressing a tendon.
Dunnage
— materials used for keeping concrete elements from touching each other or other materials
during storage and transportation.
Engineer
— a person in the engineering profession with specific expertise in precast concrete who is
licensed to practice in a jurisdiction in Canada.
Exposed aggregate concrete
— concrete manufactured so that the aggregate on the face protrudes
from the paste.
Licensed for/Autorisé à Jed Friesen Sold by/vendu par CSA on/le June/18/2015.
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