Surface active having the ability to modify surface

surface active —having the ability to modify surface energy
and to facilitate wetting, penetrating, emulsifying, dispers-
ing, solubilizing, foaming, frothing, etc., of other substances.
surface-active agent —agent, surface-active.
surface air voids —small regular or irregular cavities, usual-
ly not exceeding 15 mm in diameter, resulting from en-
trapment of air bubbles in the surface of formed concrete
during placement and consolidation. (See also sack rub .)
surface area —see surface, specific .
surface bonding (of masonry) —bonding of dry-laid mason-
ry by parging with a thin layer of fiber-reinforced mortar.
surface moisture —see moisture, surface .
surface retarder —see retarder, surface .
surface tension —an internal molecular force that exists in
the surface film of all liquids and tends to prevent the liq-
uid from flowing.
surface texture —degree of roughness or irregularity of the
exterior surfaces of aggregate particles and also of hard-
ened concrete.
surface vibrator —see vibrator, surface .
surface voids —see voids, surface .
surface water —see moisture, surface (preferred term).
surfactant —a shortened form of the term “surface-active
agent.”
surkhi —a pozzolan consisting of burned clay powder prin-
cipally produced in India.
sustained modulus of elasticity —see modulus of elastici-
ty, sustained .
sway brace —a diagonal brace used to resist wind or other
lateral forces. (See also bracing ; cross bracing ; and X-
brace .)
swelling —increase in either length or volume. (See also
contraction ; expansion ; volume change ; and volume
change, autogenous .)
swift —a reel or turntable on which prestressing tendons are
placed to facilitate handling and placing.
swirl finish —see finish, swirl .
Swiss hammer —see hammer, rebound (preferred term).
syneresis —the contraction of a gel, usually evidenced by the
separation from the gel of small amounts of liquid; a pro-
cess possibly significant in the bleeding and cracking of
fresh hydraulic-cement mixtures.
syngenite —potassium calcium sulfate hydrate, a compound
sometimes produced during hydration of portland ce-
ment, found in deteriorating portland-cement concrete
and said to form in portland cement during storage by re-
action of potassium sulfate and gypsum.
system —
system, one-way —the arrangement of steel reinforce-
ment within a slab that presumably bends in only one
direction.
system, two-way —a system of reinforcement; bars, rods,
or wires placed at right angles to each other in a slab
and intended to resist stresses due to bending of the
slab in two directions.
Système International —see SI .
systems building —see industrialized building .
T
T & G —see tongue and groove .
table, flow —a flat, circular jigging device used in making
flow tests for consistency of cement paste, mortar, or con-
crete. (See also flow, [2]).