Glossary - Design and Control of Concrete Mixtures - page 332

Shrinkage-compensating concrete —concrete con-
taining expansive cement, or an admixture, which pro-
duces expansion during hardening and thereby offsets
the contraction occurring later during drying (drying
shrinkage).
Slag cement —hydraulic cement consisting mostly of
an intimate and uniform blend of ground, granulated
blast-furnace slag with or without portland cement or
hydrated lime.
Slump —measure of the consistency of freshly mixed
concrete, equal to the immediate subsidence of a spe-
cimen molded with a standard slump cone.
Slurry —thin mixture of an insoluble substance, such as
portland cement, slag, or clay, with a liquid, such as
water.
Soil cement —mixture of soil and measured amounts
of portland cement and water compacted to a high den-
sity; primarily used as a base material under pave-
ments; also called cement-stabilized soil.
Specific gravity —see Relative density .
Stucco —portland cement plaster and stucco are the
same material. The term “stucco” is widely used to
describe the cement plaster used for coating exterior
surfaces of buildings. However, in some geographical
areas, “stucco” refers only to the factory-prepared
finish coat mixtures. (See also Portland cement plaster.)
Sulfate attack —most common form of chemical attack
on concrete caused by sulfates in the groundwater or
soil manifested by expansion and disintegration of the
concrete.
Superplasticizer (plasticizer) —admixture that in-
creases the flowability of a fresh concrete mixture.
Supplementary cementitious (cementing) mate-
rials —Cementitious material other than portland
cement or blended cement. See also Cementitious material .

W
Water absorption —(1) The process by which a liquid
(water) is drawn into and tends to fill permeable pores
in a porous solid. (2) The amount of water absorbed by
a material under specified test conditions, commonly
expressed as a percentage by mass of the test specimen.
Water to cementing (cementitious) materials ratio —
ratio of mass of water to mass of cementing materials in
concrete, including portland cement, blended cement,
hydraulic cement, slag, fly ash, silica fume, calcined
clay, metakaolin, calcined shale, and rice husk ash.
Water to cement ratio (water-cement ratio and w/c)
—ratio of mass of water to mass of cement in concrete.
Water reducer —admixture whose properties permit a
reduction of water required to produce a concrete mix
of a certain slump, reduce water-cement ratio, reduce
cement content, or increase slump.
White portland cement —cement manufactured from
raw materials of low iron content.
Workability —That property of freshly mixed concrete,
mortar, grout, or plaster that determines its working
characteristics, that is, the ease with which it can be
mixed, placed, molded, and finished. (See also Slump
and Consistency .)

X

Y
Yield —volume per batch of concrete expressed in cubic
meters (cubic feet).

Z
Zero-slump concrete —concrete without measurable
slump (see also No-slump concrete ).

T
Tensile strength —stress up to which concrete is able
to resist cracking under axial tensile loading.

U
UBC —Uniform Building Code, published by the Inter-
national Conference of Building Officials, Whittier,
California.
Unit weight —density of fresh concrete or aggregate,
normally determined by weighing a known volume of
concrete or aggregate (bulk density of aggregates in-
cludes voids between particles).

V
Vibration —high-frequency agitation of freshly mixed
concrete through mechanical devices, for the purpose
of consolidation.
Volume change —Either an increase or a decrease in
volume due to any cause, such as moisture changes,
temperature changes, or chemical changes. (See also
Creep. )