A
abrasion
resistance
How well a concrete surface or decorative coating resists
being worn away by friction or rubbing.
abrasive
blasting
Propelling an abrasive medium (such as sand or steel shot)
at high velocity against concrete to roughen, clean, or
profile the surface in preparation for decorative coatings
or overlays. Methods include sandblasting,
shotblasting, bead blasting,
and sand brushing.
accelerator
An admixture used to shorten the set time of concrete
and/or speed strength development. Accelerators are also
used to the speed the chemical reaction and shorten the
curing time of resin-based coatings.
Acetone
Common solvent. Often used as a carrier for solvent based
sealers. Considered an exempt solvent from VOC regulations.
acid etching
Application of muriatic or phosphoric acid to clean or
profile a concrete surface. Used as an alternative to
abrasive blasting for surface preparation. (Also
see neutralize.)
acid stain (or chemical stain)
A stain containing inorganic salts dissolved in an acidic,
water-based solution that reacts chemically with the
minerals in hardened concrete to produce permanent,
transparent color that will not peel or flake. Gives
concrete an attractive variegated or marbleized
appearance. Colors tend to be earth tones, such as tans,
browns, reddish browns, and greens. (Also see polymer
stain).
adhesive stencils
Adhesive-backed masking patterns made of vinyl or plastic
used for creating stenciled concrete effects. The
adhesive keeps the patterns firmly in place on the concrete
surface while the decorative treatment of choice is applied,
such as acid stains, dyes, spray-down
systems, etching gels, or sandblasting.
(Also see sandblast stenciling.)
admixture
An ingredient in concreteσother than water, portland
cement, and aggregateσused to modify the
properties of concrete in its freshly mixed, setting,
or hardened states. May be added to concrete at the batch
plant or on the job site.
Prepackaged admixtures are available for convenient job
site addition, giving contractors the ability to modify the
concrete they receive when necessary, such as extending the
amount of time available for decorative stamping.
aggregate
A
granular material such as sand, rock, crushed stone, gravel,
or other particles added to concrete to improve its
structural performance. (Also see decorative aggregate.)
air content
The amount of entrained or entrapped air in concrete,
usually expressed as a percentage of total volume.
air entrainment
Adding an air-entraining admixture to fresh
concrete to cause the development of microscopic air
bubbles. Helps to improve the freeze-thaw resistance and
durability of hardened concrete.
alligatoring
Surface
imperfections in a coating resulting in a wrinkled
appearance. Usually caused by incompatibility of a newly
applied coating with an existing surface coating or
sealer. Also know as orange peel or fish eyeing.
antiquing
A color layering technique for giving decorative
concrete surfaces an aged or mottled appearance.
B
bleed
through
Color
change caused by the diffusion of color from an underlying
surface.
bleed water
(bleeding)
Water
that rises to the surface of freshly placed concrete due to
segregation.
Bleeding may interfere with
finishing
operations. If a
dry-shake
color hardener
is being applied to the concrete surface, some bleed water
is needed to wet out the hardener sufficiently so it can be
floated into the surface.
blistering
The formation of blisters in toppings or coatings and the
loss of adhesion with the underlying substrate. On concrete
surfaces, this is often caused by moisture or moisture
vapor transmission problems.
bond
The
degree of adhesion or grip of a material (such as coatings,
toppings, repair mortars, or sealers) to an existing
surface.
bonding
agent
An adhesive agent
used to
increase the adherence of coatings or toppings to the
existing surface. Also used to bond new concrete to old.
Also known as a primer.
bond
breaker
A
material that prevents adhesion of materials to a concrete
substrate.
broadcast
To hand toss a dry-shake color hardener,
decorative aggregate, or other dry material in a uniform
layer over fresh concrete, overlays, or coatings to
add color or traction. (Also see seeding.)
broom finish
Surface texture obtained by pushing a broom over freshly
placed concrete.
build
The wet
or dry thickness of a coating or topping. (Also see
high-build coating
bull float
A tool with a 3- to 4-foot rectangular blade made of wood,
resin, aluminum, or magnesium. Used to eliminate high and
low spots in freshly placed concrete slabs, embed large
aggregate at the surface, bring a layer of paste to the
surface needed during final finishing, and float in
dry-shake color hardener. Long handles either clip on
or screw into the float head so it can be pushed out onto
the slab while the user stands at the perimeter. (Also see
hand float.)
bush hammer
A percussive hammer with rows of pyramid-shaped points
used to roughen or profile a concrete surface.
C
calcium
chloride vapor-emission test
An ASTM test used to measure the volume of moisture vapor
released from a concrete substrate over time (typically 24
hours). Too much moisture emitted from a slab can affect the
performance and bonding of overlays, coatings, and sealers.
Moisture vapor test kits are available that include
small containers of preweighed, unhydrated calcium chloride.
cast in
place
Concrete
placed and finished in its final location.
cement replacement -
(or supplementary cementitious material) A material
used in concrete as a partial replacement for portland
cement. Includes pozzolans, fly ash, and
granulated blast furnace slag. Can have positive
effects on decorative concrete by improving
finishability, reducing permeability, and reducing
efflorescence.
cementitious
A
material containing
portland
cement
as one of its components or having cement-like properties.
chalking
Loose,
powdery substance caused by deterioration of a concrete
surface or degradation of a coating or overlay.
coating
system
A
complete system requiring a number of coats of material to
be applied separately in a predetermined order and at
prescribed intervals to allow for sufficient drying and
curing. May include a
primer,
one or more intermediate coats, and a topcoat.
compressive
strength
The
maximum compressive stress concrete or cementitious
overlay materials are capable of sustaining, expressed as
pounds per square inch (psi).
color chips
Plastic
chips, available in various colors and sizes, for
broadcasting onto freshly placed epoxy resin
flooring systems, such as epoxy terrazzo, to produce
multicolored effects.
color
layering
Applying layers of color to achieve variegated or faux
finish effects, such as antiquing or marbleizing.
For example. a dry-shake color hardener may serve as
the base color, accented by a pigmented powdered or liquid
release agent, followed by additional accenting with
acid stains, dyes, or tints.
concrete countertops
A
handcrafted alternative to manufactured countertop surfaces.
Can be precast in a shop in molds built to the customerνs
specifications or cast onsite, by setting a mold on top of
the base kitchen cabinets and then filling with concrete.
The use of stains, pigments, decorative aggregates,
and epoxy coatings can give concrete countertops the look,
texture, and feel of quarried stone such as marble, granite,
and limestone.
concrete
surface profile (CSP)
The degree of roughness of a concrete surface achievable
with various surface preparation methods. The
International Concrete Repair Institute has identified
nine distinct roughness profiles considered to be suitable
for the application of sealers, coatings, and
polymer-modified overlays.
consistency
The ability of fresh concrete to flow. The usual
measure of consistency is slump.
control (or
contraction) joint
Sawed or tooled groove in a concrete slab used to regulate
the location of cracking.
coverage
rate
The area
that a specified volume of coating will cover to a specified
thickness upon drying.
crack
chasing
Routing
out cracks in concrete with a saw or angle grinder before
filling with a repair material.
crack
stitching
A method of repairing cracks that involves drilling holes
on both sides of the crack and grouting in wire or U-shaped
metal strips that span the crack.
cracks,
moving
Cracks
in concrete that are still moving, or active. Often
they are structural in nature and continue through the
entire depth of the concrete.
cracks,
static Random, non-moving hairline cracks that only
affect the concrete surface (also see craze cracks
and plastic shrinkage cracks).
craze
cracks
A series of fine, random cracks caused by
shrinkage of the surface mortar.
crusting
A condition that occurs when the surface of freshly placed
concrete dries too quickly, often due to exposure to direct
sun, wind, or high temperatures.
curing
Action taken to maintain favorable moisture and
temperature conditions of freshly placed concrete or
cementitious materials during a defined period of time
following placement. Helps to ensure adequate hydration
and proper hardening.
curing
compound
A liquid that, when applied to the surface of newly placed
concrete, forms a membrane on the concrete or penetrates the
concrete to retard the evaporation of water.
D
darby
A
longer version of a hand float, ranging in length
from 2 to 4 feet. Useful for leveling problem areas.
decorative aggregate
Richly colored natural stones, such as basalts, granite,
quartz, or limestone, used to enhance exposed-aggregate
concrete or decorative toppings.
decorative concrete
Concrete that has been enhanced by color, pattern, texture,
or a combination of ornamental treatments.
degreaser
A chemical
solution for removing grease, oils, and other contaminants
from concrete surfaces.
delamination
A separation of a coating or topping from a substrate or
the layers of a coating from each other due to poor
adhesion. Or in the case of a concrete slab, a horizontal
splitting or separation of the upper surface.
densifier
A penetrating liquid chemical hardener applied to concrete
to help solidify and densify the surface and provide extra
protection from water penetration and staining. Often
recommended for
polished
concrete,
because hard concrete produces a better polish.
diamond
grinding
A
multistep grinding procedure for producing polished
concrete surfaces. Contractors use a floor polisher
equipped with diamond-segmented abrasives, progressing from
coarser to finer grits until the desired level of sheen is
achieved. (Also see dry polishing, wet polishing.)
dry
polishing
The
method most commonly used for
polished concrete.
The
floor polisher
is hooked up to a dust-containment system that vacuums up
the dust from
diamond
grinding
of the surface. (Also see
wet
polishing.)
dry-shake color hardener A mixture
of coloring pigments, cement, aggregates, and surface
conditioning agents. Applied as a dry shake to stamped
concrete or stamped overlays to produce a
colorful, wear-resistant surface.
drying
shrinkage
A
decrease in the volume of concrete as it dries, due to loss
of moisture. See also plastic shrinkage cracks
dyes
Translucent color solutions containing very fine pigments
that penetrate into the concrete surface. Will not
chemically react with concrete (like acid stains will). Both
water-and solvent-based dyes are available, with colors
ranging from soft pastels to bolder hues such as red, blue,
and orange.
E
edger
A tool used on the edges of fresh concrete to provide a
clean, finished edge.
engraving
The use
of special tools and equipment to cut or route out patterns
and designs in hardened concrete. Usually the concrete is
stained first to give it color, so the routed areas look
like grout lines.
efflorescence
A
crystalline deposit of salts (usually white in color) that
forms on the concrete surface when soluble calcium
hydroxides leach from the concrete and combine with carbon
dioxide in the atmosphere. On colored concrete, especially
darker tones, these white deposits can be particularly
unsightly.
epoxy injection
A method for sealing or repairing cracks in concrete by
low-pressure injection of an epoxy adhesive.
epoxy resins
Organic chemical bonding systems used in the
preparation of protective and decorative coatings for
concrete, adhesives for injection of cracked concrete, or as
binders in epoxy mortars.
epoxy terrazzo
A poured-in-place topping
for concrete substrates that goes on at a thickness of 1/4
to 3/8 inch. The epoxy resin
matrix can be pigmented to achieve an unlimited spectrum of
colors and is often seeded while still wet with decorative aggregates
or color chips.
etching gel A gentle
etching medium often used with adhesive stencils to lightly etch designs in concrete surfaces. The
material is thick enough to be applied by brush, permitting
controlled application.
evaporation retarder
A waterborne, spray-applied film that
temporarily reduces moisture loss when applied to the
surface of freshly placed concrete.
expanded
metal lathe
A sturdy but flexible diamond mesh often used as a
framework or support system for concrete sculptures,
faux
rock,
and
vertical stamped concrete.
exposed aggregate
A decorative surface formed by removing the surface mortar
from a concrete slab (either by scrubbing, pressure washing,
or abrasive blasting) to expose the underlying
aggregates. (Also see surface retarder.)
F
faux rock
An
artificial rock formation sculpted or molded from concrete
and then textured and colored to replicate the look and feel
of natural rock. Popular applications include waterscapes,
zoo exhibits, landscaping, and theme parks. (Also see
glass-fiber reinforced concrete.)
feather
edge
To
smoothly, seamlessly blend the edge of a topping or repair
material into the existing concrete.
fibers
Tiny
filaments made of polypropylene, polyolefin, nylon,
polyethylene, polyester, or acrylic used alone or in
conjunction with rebar or welded wire mesh to reinforce
concrete.
finishing
Leveling, smoothing, compacting, and otherwise
treating the surface of newly placed concrete or concrete
overlays to produce the desired appearance and service
properties.
film-forming sealer
A type of sealer that blocks the penetration of
water and contaminants by forming a barrier on the concrete
surface. May also impart a gloss or sheen, which enhances
colored or exposed aggregate concrete. See also
membrane.
film
thickness
The depth of the film when wet (wet film thickness) and the
final depth when dry (dry film thickness).
flashing
(or flash broadcasting)
A
technique for applying accent colors of dry-shake
hardener to concrete surfaces before stamping. Results
in subtle, natural-looking color variations.
flexural
strength
The ability of hardened concrete or an overlay to
resist failure in bending.
float finish
Surface texture (usually rough) obtained by finishing
with a bull float or hand float.
floor
polisher
A walk-behind machine used in the production of
polished
concrete.
Most machines are equipped with a planetary drive systemσa
large primary polishing head (from 17 to 36 inches in
diameter) fitted with three or four smaller satellite heads
that hold the diamond abrasives. When the machine is
operating, the satellite heads rotate in the opposite
direction of the primary head to eliminate linear grinding
marks in the floor. (Also see
diamond grinding,
dry polishing,
wet polishing).
fly ash
A byproduct resulting from the combustion of ground or
powdered coal; sometimes used as a cement replacement
in concrete.
form liner
Material used to line the interior face of formwork in
order to impart a smooth or patterned architectural finish.
fresno
A
large
trowel
(about 2 to 4 feet in length) used for final
finishing
after bull floating.
Long
handles (like those used for
bull floats)
either clip on or screw into the blade.
G
gauge
rake
A tool
with an adjustable depth gauge designed for application of
high-build coatings
or
cementitious
toppings
at a preset, uniform thickness.
glass-fiber reinforced concrete (GFRC)
A
portland
cement-based
composite containing glass fibers for reinforcement.
Substantially lower in weight than plain concrete, with
higher
flexural
and
compressive strengths.
Often used in the production of
faux
rock
formations and
concrete
countertops.
granulated
blast furnace slag
A
glassy, granular material formed when molten blast furnace
slag is rapidly chilled. Ground granulated slags are
sometimes used in concrete mixtures as a cement
replacement to help reduce permeability and
improve durability. May also slow setting and extend
the working time of the concrete.
grinding
A
mechanical surface preparation method using rotating
abrasive stones or discs to remove thin coatings and mastics
or slight flaws and protrusions.
groover
A tool with a V-shaped bit used to create
control joints in plastic concrete.
grout
A
mixture of
cementitious
materials and water, with or without
aggregate,
proportioned to produce a creamy consistency. Can be
purchased preblended in a multitude of colors to define
joints and
sawcuts in
decorative
concrete
slabs or
walls, especially those with stone, brick, or tile patterns.
H
hand
float
A
smaller handheld version of the bull float, ranging
in length from 12 to 18 inches. Especially useful for
floating along the perimeter of forms or to work in tight
spots.
hard-troweled finish
Surface finish obtained by using a trowel with a
steel blade for final finishing of concrete. Often
used where a smooth, hard, flat surface is desired.
high-build coating
A
protective or decorative coating that produces a thick film
(usually greater than 10 mils) in a single coat.
high-pressure water blasting
A
process for cleaning or roughening concrete surfaces using a
stream of water delivered at high pressure.
high-volume
low-pressure (HVLP) sprayer
A
spraying device that applies high-solids paints and coatings
at low pressure and low velocity, to reduce overspray.
hopper gun
A
gravity-fed system for spray application of
coatings
or
toppings.
The material is placed in a hopper attached to a spray gun,
which is powered by an air compressor. Often used to apply
spray-down systems.
HoverTrowel
A patented lightweight power trowel developed specifically
for precision finishing of epoxy,
polymer
modified,
and
cementitious
overlay systems.
hydration
The chemical reaction between cement and water that causes
concrete or other cement-based materials to harden.
I
integral color
A coloring agent premixed into fresh concrete or
cementitious toppings before placement.
iron oxide
An
inorganic pigment often used to color decorative coatings
and toppings.
J
joint (control, expansion, or isolation)
Formed, sawed, or tooled groove in a concrete slab used to
regulate the location of cracking (control joint) or
to allow expansion or movement of adjoining structures. In
decorative concrete, joints can also double as delineating
design elements in a pattern.
joint
filler
A
compressible material used to fill a
joint
to prevent the infiltration of debris.
K
kerf
A cut in
a concrete surface made by a saw or router.
(Also
see
sawcutting.
kneeboards
Boards
used by concrete finishers to kneel on when hand floating or
troweling concrete flatwork. (Also see
spiked
kneeboards.)
knock-down finish
Achieved by applying a decorative topping with a hopper
gun and then using a trowel to μknock-downξ the
material to produce a smooth or lightly textured surface.
L
laitance
A thin
layer of fine, loosely bonded particles on the surface of
fresh concrete, caused by the upward movement of water.
Laitance must be removed before application of a decorative
coating or topping.
M
marbleize
To give
concrete surfaces the look and gloss of marble, through a
combination of color layering and finishing
techniques.
margin
trowel (also pointer or pointed masonνs trowel)
A
steel trowel with a small, rectangular flat blade about 5 to
8 inches in length and a short handle. It has multiple uses,
including scraping off concrete from finishing tools and
applying patching materials.
masking
Covering
select areas of a concrete surface with an adhesive
stencil, tape, or other medium before applying a
decorative treatment that will affect only the exposed
areas.
material
safety data sheet (MSDS)
Information sheets containing pertinent chemical
ingredients, product handling and safety guidelines.
membrane
Formed
over a concrete surface to provide protection and enhance
color. Typically clear plastic like acrylic, polyurethane
or epoxy.
microtopping
An ultra-thin polymer-based decorative
topping,
generally less than 1/4-inch total thickness. Typically
applied by
trowel or
squeegee, and given a texture or smooth finish.
Pigments
can be incorporated into the mix or
broadcast
onto the surface for a
marbleized
appearance. (Also see
skim coat.)
mil
A measurement equal to 1/1,000 (0.001) inch. Commonly used
to denote coating thickness.
mix
design
Specific proportions of ingredients (cement, aggregates,
water, and admixtures) used to produce concrete suited for a
particular set of job conditions.
mixing
station
A
designated work area outfitted with all the equipment and
supplies needed to mix materials properly and efficiently.
mockup
An
architectural concrete sample made using the same materials
and methods proposed for an actual project. Often required
for quality assurance on large projects, to ensure that
architectural requirements and industry tolerances are met.
The size should be sufficient to adequately demonstrate all
decorative treatments.
moisture vapor transmission
The migration of moisture vapor to the surface of a
concrete slab, caused by vapor pressure differentials in the
concrete and the surrounding atmosphere. Can contribute to
the failure of impermeable coatings or other floor toppings
that do not permit moisture to escape. (Also see calcium
chloride vapor-emission test.)
N
neutralize
To return concrete to the proper pH after acid etching,
generally by washing the surface with a mixture of water
and ammonia or sodium carbonate. Ideal pH is 7.0 (neutral),
but a pH range of 6.0-9.0 is acceptable for most coatings.
ASTM D 4262, "Standard Test Method for pH of Chemically
Cleaned or Etched Concrete Surfaces," covers the
procedure for determining the acidity or alkalinity of
concrete surfaces prepared by chemical cleaning or etching
prior to coating application. See pH test.
notched-squeegee
A rubber squeegee with notches or serrations on one or
both edges. Used for smooth and consistent spreading of
epoxy resin products or other low-viscosity
coatings.
O
opacity
The
ability of a coating to hide the color of the underlying
surface. See translucent.
overlay
A bonded layer of material, ranging from 1/4 to 1 inch or
more in thickness, placed on existing concrete surfaces to
beautify, level, or restore. (Also see polymer-modified
overlay, self-leveling overlay.)
P
penetrating sealer
A sealer
with the ability to penetrate into the concrete
surface to increase water repellency and resist stains.
Often used on decorative concrete to provide
invisible protection without changing the surface
appearance.
permeability
The degree
to which a membrane or coating will allow the passage
or penetration of a liquid or gas.
pH Test
A test performed on the concrete surface to
determine the level of acidity or alkalinity. Typically
performed prior to applying sealers or coatings.
pigment
A finely ground natural or synthetic particle adding color
and opacity to a coating or topping.
pinholing
A defect in a coating characterized by pinhead-sized holes
that expose the underlying substrate.
plastic
A condition of freshly mixed concrete indicating that it
is workable and readily moldable.
plastic shrinkage cracks
Irregular cracks that occur in the surface
of fresh concrete soon after it is placed and while it is
still plastic.
plasticity
Property of freshly mixed concrete, cement paste, or
mortar which determines its ease of molding or resistance to
deformation.
platform tools
Rigid stamps
made of plastic or metal that leave deep grooves in freshly
stamped concrete, which can later be grouted or left
open.
polished concrete
- A
high-gloss finish attained by using special floor
polishers fitted with diamond-impregnated abrasive disks
(similar to sandpaper) to grind down surfaces to the desired
degree of shine and smoothness. The resulting surface is
very low-maintenance and can be stained to replicate the
look of polished stone. (Also see dry polishing,
wet polishing, diamond grinding.)
polymer-modified overlay
A
cement-based overlay with polymer resins added to improve
performance, wear resistance, and aesthetic qualities.
Overlay manufacturers use different types of polymer resins,
often blending them to produce proprietary products with
unique characteristics. Many of todayνs decorative overlays
use acrylics or vinyl blends because these resins provide
excellent bond strength and UV resistance.
polymer stain
An acrylic-urethane based stain available in a broader
palette of colors than acid stains. Very low in
volatile organic compounds, with workability
characteristics similar to latex paint. Can be applied to
concrete surfaces by brush, roller, sponge, cloth, or
commercial sprayer.
popout
A
pit or crater in the concrete surface, ranging in size from
1/4 inch to several inches in diameter, that results
from the fracturing of unsound aggregate particles
due to expansion pressure. Usually caused by porous
aggregate having a high rate of absorption.
pot life
The length
of time a material is useful after its original package is
opened or a catalyst is added.
profile
The act of
preparing a concrete surface to achieve the necessary degree
of roughness (also see concrete surface profile).
portland cement
A hydraulic product that sets and hardens
when it chemically interacts with water. Made by burning a
mixture of limestone and clay or similar materials. (Also
see white cement.)
pozzolan
A
siliceous and aluminous material that, in the presence of
moisture, chemically reacts with calcium hydroxide to form
compounds possessing cementitious properties. (Also
see cement replacement).
primer The first coat of
material applied to a concrete surface to improve bonding or
adherence of subsequent coats. See also bond coat.
pump-up sprayer
An airless
sprayer often used to apply
sealers
and liquid
release
agents.
R
raveling
The
dislodging of
aggregate
at the edges of
joints
or scored patterns in concrete, generally caused by
sawcutting
joints too soon after concrete placement.
ready-mixed concrete
Concrete
thatνs batched or mixed at a central plant before delivery
to the job site for placement.
rebar (or reinforcing bars)
Ribbed
steel bars installed in cast-in-place concrete to provide
flexural strength. Rebar come in various diameters and
strength grades.
reentrant corner
An angle in a concrete slab that points inward. Often
vulnerable to cracking, unless a control joint is
installed.
reflection cracking
The occurrence of cracks in overlays and toppings that
coincide with the location of existing cracks in the
substrate.
reinforced
concrete
Concrete construction that has steel rebar or
welded wire mesh embedded in it to provide greater
tolerance to tension and flexural stress.
release
agent
A powder or liquid parting agent applied to stamping
mats or texturing skins before stamping to keep
the mats from sticking to fresh overlay or concrete
surfaces.
rustication
strip
A strip
made of wood, polystyrene, or plastic thatνs fastened to
forms or form liners to impart architectural details
to wall surfaces.
S
sacrificial
coating
A final
floor finish or wax designed to protect the sealer or
topcoat from wear. Usually applied by mop or floor buffer in
several coats to act as a shock absorber to scuffs,
scratches, and grime.
salt finish
A textured,
decorative finish obtained by broadcasting rock salt
onto fresh concrete and then using a roller or float
to press the salt particles into the surface. After the
concrete sets, the salt is washed away to reveal a speckled
pattern of shallow indentations.
sample (or
sample board)
A small
(generally 2x2-foot) representation of a decorative
concrete installation, used as a selling tool or to
experiment with various decorative treatments and techniques
for applying materials.
sandblast stenciling
A technique
for patterning existing concrete surfaces by applying
resilient adhesive stencils followed by
sandblasting to lightly remove concrete in only the
exposed areas. (Also see stenciled concrete.)
sandblasting
A method of
abrading or profiling a surface with a stream of sand
ejected from a nozzle at high speed by compressed air. (Also
see abrasive blasting.)
saturated
surface dry (SSD)
Condition
of concrete when the permeable voids are filled with water
but no water is on the exposed surface.
sawcutting
Using a concrete saw with abrasive blades or disks to cut
joints or score patterns into hardened concrete.
scaling
The flaking or breaking away of a hardened concrete
surface, often due to exposure to freezing and thawing.
scarifier
Milling equipment used to clean and profile
concrete surfaces or to remove existing coatings. Uses
rotary impact cutters held at a right angle to the surface.
sealer
Solvent- or liquid-based material used to protect and
enhance the appearance of decorative concrete. (Also see
film-forming sealer and penetrating sealer.)
seeding
Broadcasting decorative aggregates on the surface of
freshly placed concrete or toppings.
segregation
The separation of the components of wet concrete caused by
excessive handling or vibration.
self-leveling overlay
A flowable, polymer-modified cementitious topping with the
ability to self level without troweling. Used to smooth and
level existing concrete surfaces. Can also be enhanced by
staining, dying, or sawcutting.
set
The condition reached by concrete when plasticity
is lost, usually measured in terms of resistance to
penetration or deformation. Initial set refers to concrete
that has reached first stiffening. Final set occurs when
concrete attains full rigidity.
setting
The chemical reaction that occurs after the addition of
water to a cementitious mixture, resulting in a
gradual development of rigidity.
scratch
coat A base coat used to improve the rigidity and/or bonding of
subsequent topcoats. A scratch coat is often required for
vertical stamped concrete.
screed
box
A
walk-behind applicator, similar in appearance to a
lawn fertilizer spreader, designed to put down epoxy coating
systems at a specific depth.
shotblasting
An
abrasive blasting method using round iron shot to
clean and profile concrete surfaces.
skim
coat
An overlay layer applied very thinly with a squeegee or
trowel. (Also see microtopping.)
Solvent
Liquid typically used as a carrier for sealers and curing compounds.
spalling
A breaking away of concrete at joints in floors or
slabs. Typically occurs at joints that are installed
improperly or donνt adequately support the loads applied to
them. (Also see raveling.)
spray-down system
A decorative overlay applied as a splatter coat
or a knock-down finish to a thickness of about 1/8
inch. Often used in conjunction with paper or adhesive
stencils. Available precolored or can be integrally
colored during mixing.
slump
A measure of consistency of freshly mixed concrete, as
determined by the distance the concrete μslumpsξ after a
molded specimen is removed from an inverted funnel-shaped
cone.
spiked
kneeboards Kneeboards
with spikes on the bottom that elevate finishers off floor
surfaces to permit easier finishing of toppings and
overlays.
spiked
roller
A
cylindrical tool similar in appearance to a paint roller,
but with rows of polypropylene spikes. Used to roll across
the surface of freshly applied epoxy coatings to release
trapped gas bubbles and to assist in leveling.
splatter
coat
A coating or topping applied by μsplatteringξ it onto the
surface, typically by dipping a brush into the material and
then flicking it.
stamped concrete
Concrete flatwork that is patterned with
platform tools, stamping mats, or seamless
texturing skins to resemble materials such as
brick, slate, stone, tile, and wood planking. (Also see
vertical stamped concrete.)
stamped
overlay
Similar
to conventional
stamped concrete,
but can
be applied to existing concrete. A cementitious topping is
applied at a thickness of 1/4 to 3/4 inch and then stamped
to mimic brick, slate, and natural stone. Color options
include
dry-shake
color hardeners,
colored liquid or powdered
release agents,
acid stains,
dyes, and
tinted
sealers.
stamping
mats
Rigid or semi-flexible polyurethane tools for imprinting
stone, slate, brick, and other patterns in stamped
concrete surfaces. Stamping mats usually imprint a
shallower pattern than platform tools.
static
cracks
Random, non-moving hairline cracks that only affect the
concrete surface (also see craze cracks and
plastic shrinkage cracks).
stenciled concrete
A decorative surface treatment using heavy-duty paper
stencils with stone, tile, or brick patterns that are
lightly pressed into fresh concrete, followed by the
application of dry-shake color hardeners. When
the stencils are removed, the uncolored concrete mimics
mortar joints. Another technique, for use on existing
concrete, is to apply adhesive stencils and then
color, etch, or sandblast the surface. (Also see
sandblast stenciling.)
straightedge
A rigid, straight piece of wood or metal used to strike
off a concrete surface to proper grade before the
floating operation.
strike off
To level off freshly placed concrete to the correct
elevation.
substrate
An existing concrete surface that receives an overlay,
decorative or protective coating, repair procedure, or other
resurfacing treatment.
surface preparation
Preparing
concrete surfaces prior to resurfacing or application of a
decorative coating to remove contaminants and minor defects
or to obtain the necessary degree of roughness for adequate
bonding. (Also see abrasive blasting, acid etching,
and grinding.)
surface
retarder
A chemical applied to the surface of newly placed concrete
to delay setting of the cement paste so it can be removed
easily later by scrubbing or power washing to produce an
exposed aggregate finish.
T
tack
The stickiness or adhesiveness of a material.
tamper (or
pounder)
A handheld impact tool used to firmly press stamping
mats or texturing skins into fresh concrete to
ensure a complete imprint.
technical
data sheet
Contains
important specifications and manufacturer guidelines for
product usage. Includes such data as coverage rates,
recommended applications, product limitations, surface
preparation guidelines, mix ratios and required mixing
times, pot life, application procedures, cure times,
performance data, and precautions.
texture
roller
A
cylindrical tool similar in appearance to a paint roller
used to impart a stonelike texture to stenciled concrete.
It is rolled over the stencil and the fresh concrete to
texture only the exposed surfaces.
texturing
Giving concrete or overlay surfaces a texture
without leaving deep pattern lines.
texturing
skins
Flexible
skins for adding seamless textures to concrete surfaces.
Generally thinner and more pliable than stamping mats.
Often used to texture slab perimeters and vertical faces,
such as stair risers. Can also be used to fix blemishes from
nonuniform stamping.
tint A diluted color wash used to add hints of color to decorative
concrete.
trowel
A flat, broad-bladed steel hand tool used to compact the
paste layer at the surface and provide a smooth, flat
finish. Also useful for applying topping or repair
materials. Available in different shapes (with rounded or
square edges) and lengths (ranging from 8 to 24 inches).
Smaller trowels are useful for borders, work in restricted
areas, or to work in flashing accents of dry-shake
color hardener. (Also see margin trowel,
fresno).
trowel finish
The smooth or lightly textured surface finish obtained by
troweling.
Translucent A type of finish were the coating has some
level of transparency.
V
vapor
barrier
A moisture-impervious material, such as plastic sheeting,
placed on the subbase under a concrete slab to help prevent
moisture vapor transmission.
vertical stamped concrete
A
decorative finish for walls and other vertical surfaces
using a lightweight cementitious overlay formulated
to be applied at thicknesses of up to 3 inches without
sagging. While the overlay is still plastic,
it can be stamped or hand carved to produce deep-relief
stone or masonry wall textures. After the material dries,
acid stains or dyes can be sprayed or sponged
onto the surface to give it the multi-toned look of natural
stone.
viscosity
A measure of the fluidity of a liquid material. The more
viscosity a material such as a sealer or coating has,
the less it flows.
volatile
organic compounds (VOCs)
Organic chemicals that readily vaporize at normal room temperatures.
Concrete coatings, sealers, or cleaning materials
that are solvent-based generally have higher VOC contents
than water-based materials. Some VOCs can be hazardous when
inhaled.
W
water-cement ratio The
ratio of the amount of water to the amount of cement in a
concrete mixture. The key to producing high-quality
decorative concrete is to keep the water-cement ratio as low as possible without
sacrificing workability.
water plug
A
hydraulic cement used to fill cracks and to prevent the
migration of moisture.
water reducer
An admixture that either increases the slump
of freshly mixed concrete without increasing water content
or maintains workability with a reduced amount of
water without affecting the strength.
welded wire mesh
A woven mesh
of wire strands, welded at each intersection, used to
reinforce concrete slabs. Also called welded wire fabric.
wet polishing
A method
for
polished concrete
that uses water to cool the diamond abrasives and eliminate
grinding dust. Not as commonly used as
dry
polishing,
because the process creates a tremendous amount of slurry (a
soupy mixture of water and cement dust) that must be
collected and disposed of.
white cement
A portland cement with a low iron content that
hydrates to a white paste. Often used in integrally
colored concrete to produce pure, bright color tones,
especially pastels.
workability
The ease with which concrete or other cementitious
materials can be mixed, placed, and finished.
working time
The amount of time available for placing and finishing
a cement-based material before it begins to set.
Often depends on the ambient temperature and substrate
temperature.
X
xylene
A common solvent. Used as a carrier for
solvent based sealers. High in odor and flammability.