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Table of Contents
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A
Abrasive Aggregate
Aggregate that is used to increase the abrasive surface of concrete.
Absolute volume
In concrete, the actual volume occupied by the different ingredients determined by dividing the weight of each ingredient in pounds by its specific gravity, times the weight of one cubic foot of water in pounds. Example: Absolute Volume of one sack of cement equals: 94 ÷ (3.15 x 62.4) = 0.478 cubic feet.
Accelerator
An admixture used to shorten the set time of concrete and/or speed strength development. Accelerators can also used to the speed the chemical reaction and shorten the curing time of resin-based coatings.
ACI
American Concrete Institute. An International organization dedicated to providing knowledge and information for the best uses for concrete.
Acid Stain
Acid stains are made by dissolving mineral salts in a diluted hydrochloric acid (muriatic acid). The colors are determined by the different minerals.
Example: Copper_Sulphate and Copper(II)_chloride will turn concrete green / blue.
Ferrous Sulphate and Iron Chloride will turn brown / tan or terracotta.
The acid opens the pores of the concrete surface and the mineral salts change the color of the aggregates.
Acrylic Polymer
Usually in the form of a white milky liquid, this additive is used to replace some of the water content in the mix. It does not change the hydration process of Portland, but changes the permeability by lessoning the loss of water by evaporization. This can be a plus in hot dry climates. It also increases bonding strength between the cement paste and aggregates. By creating a film as it cures, Acrylic polymer also helps reduce efflorescence. The quality is base on solids % content. The preferred is a range from 45% to 51%. Two examples of popular Acrylic polymers are Forton and Polyplex.
Admixture
A material that is added to a mix that will modify its properties.
Admixes are divided into five classes:
Air-entraining
Water reducing
Retarding
Accelerating
Plasticizers or Super Plasticizers
Acrylic Sealer
Is a simple sealer that is either water or solvent based. It is a single component polymer that provides moderate stain protection and is easily scratched.
Aggregates
Aggregates can range in size from powdered silica to crushed stone. A typical concrete mix has aggregates ranging in this spectrum of sizes. Aggregates are a necessary element in concrete that allows the Portland paste to bond. Aggregates can also be man-made, such as glass fiber for GFRC or Perlite which is used in vertical carved wall mixes.
Aliphatic Urethane
A two component, clear polyester high solids protective coating. It is typically used as a topcoat for basic epoxies. Very resistant to staining, scratches and solvents. It is usually used on concrete floors in showrooms, firehouse floors and shops but has been used on concrete countertops.
Alkalis
Sodium and Potassium which occur in Portland cement, either as solid solutions in the cement compounds, or as water soluble compounds.
Alkali Silica Reactivity
The reaction of aggregates, which contain some form of silica or carbonates with sodium oxides or potassium oxides in cement, particularly in warm, moist climates or environments, causing expansion, cracking or popouts. In GFRC applications the glass fibers must be alkaline resistant.
Anhydrous Aluminum Silicate
Calcined Clay or Kaolin. Packaged under the name Metakaolin. Also known as Calcined China Clay or Calcined Kaolin. Used as a pozzolan in mixes. Primarily mined in the state of Georgia here in the US. Tradename: Kaorock
Apron Front Sink
Also referred to as a farmhouse sink. This is a sink that has a large apron in front and sits on a short cabinet.
AR – Alkali Resistant Glass Fiber
Alkali resistant fibers are necessary because they will be resistant to Aqeous solutions found in concrete. The most common is a glass fiber with a Zirconium content of 16% or more. These fibers are used during the mix of the second coat that is applied in the GFRC process.
Armatur
Commonly used in Ferro Cement creations. An armature is a framework around which an object is built. The armature provides the initial shape and stability. Can be made from anything from a wire wrapped wood frame to one built from steel rods or re-bar.
ASR
Alkali-silica reaction. ASR
ASTM
American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. The organization's headquarters is in West Conshohocken, Pennsylvania, about 5 miles northwest of Philadelphia.
B
Batch Weights
The measured amount of stone, sand, cement and admixes that make up a batch or “load” of concrete.
Blast Furnace Slag
A non metallic product that consists of mainly silicates and aluminosilicates of calcium and other bases, that is developed in a molten condition simultaneously with iron in a blast furnace.
Blended Cements
A product consisting of a mixture of Portland cement and other materials such as granulated blast-furnace slag, pozzolan, etc. This mixture is combined either during the finish grinding of the cement or by blending the material after grinding.
Bugholes
Small holes caused by air that was entrapped near the surface. Some are readily seen upon de-molding and some appear after grinding or polishing. Typical fix is to fill in voids with a cement slurry paste that matches the color of the final product. Bugholes are more prevalent with wet casting as opposed to GFRC.
Backup Mix
The GFRC mixture that is cast into the mold behind the face coat
C
Calcium Silicate Hydrate
Is the main product of the hydration of Portland cement. It is responsible for the strength in cement based materials. It is the reaction between the silicate phases of Portland cement and water.
Calcium Carbonate
Common substance found in the form of rock in most parts of the world. It is the main component of eggshells, mollusk shells, agricultural lime, chalk, marble etc. Sometimes used as an ingredient for slurry mix to fill in bugholes and voids for “pressed veining” method.
Calcium Chloride
It is a naturally occurring salt and is a solid at room temperature. It is used in the concrete industry as an accelerant to increase the early set time and early strength. It is commonly used as an ingredient for vertical wall mixes.
Calcined
To heat a substance to a high temperature but below the melting or fusing point, causing loss of moisture, reduction or oxidation, and the decomposition of carbonates and other compounds. A perfect example of a calcined product is Kaolin Clay, sometimes marketed as Metakolin.
Cantilever
A beam that projects beyond its supports. An area where a countertop overhangs a cabinet or support by more than a few inches.
Capillary Space: A term used to describe air bubbles that have become embedded in cement paste.
CCI
Concrete Countertop Institute.
CCIC
Concrete Countertop Industry Conference.
Cellular Concrete
High air content of high void ratio concrete resulting in low density.
Cement
In the most general sense of the word, a cement is a binder, a substance which sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term "opus caementicium" to describe masonry which resembled concrete and was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick additives which were added to the burnt lime to obtain a hydraulic binder were later referred to as cementum, cimentum, cäment and cement. Cements used in construction are characterized as hydraulic or non-hydraulic.
The most important use of cement is the production of mortar and concrete - the bonding of natural or artificial aggregates to form a strong building material which is durable in the face of normal environmental effects.
Cement should not be confused with concrete as the term cement explicitly refers to the dry powder substance. Upon the addition of water and/or additives the cement mixture is referred to as concrete, especially if aggregates have been added.
Cenospheres
Cenospheres are a very small spherical particle that is the naturally occurring by-product of the burning process at coal burning power plants. They are lightweight, inert, hollow and filled with air or gas.. The color varies from grey to almost white.Cenospheres are hard, rigid, insulative and waterproof. They are used in a variety of products and are now used as filler in cement. Since they are inert, Cenospheres are not considered a Pozzolan and are considered a aggregate. Replacements of up to 33% of the sand with Cenospheres can greatly reduce concrete weights to as low as 124 lbs. per square foot. Because of the round shape it is an excellent candidate to use in a bughole fill mix.
Cladding
Is a GFRC exterior wall panel material.
Clinker
In the manufacture of Portland cement, clinker is the solid material produced by the cement kiln stage that has sintered into lumps or nodules, typically of diameter 3-25 mm. Clinker, if stored in dry conditions, can be kept for several months without appreciable loss of quality. Because of this, and because it can easily be handled by ordinary mineral handling equipment, clinker is traded internationally in large quantities. Cement manufacturers purchasing clinker grind it as an addition to their own clinker at their cement plants. Manufacturers also ship clinker to grinding plants in areas where cement-making raw materials are not available.
Cohesion
Mutual attraction by which elements of a substance are held together.
Contraction Joint
Weakened plane to control racking due to volume change in a concrete structure. Joint may be groove, sawed, or formed. Also known as a control joint.
Color Hardener
The main goal of color hardener is to add strength as well as color. The color hardener should not interfere with the chemical process of the cure which is already taking place. Color hardeners are made up of five simple components: Oxide pigments for color, silica sands, calcium carbonate, portland cement and sugar. Each individual material serving a very important purpose.
Compressive Strength
The ability of concrete to resist compression forces, or pushing together forces, expressed in psi.
Control or Contraction Joint
Molded, sawed or tooled groove in a concrete slab used to regulate cracking.
CSA or Calcium Sulfoaluminate
CSA is a high strength early set Portland replacement.CSA was invented in China in the early 70s. CSA cements are very “green” and produce 62% less emissions than does the production of Portland. The main mineral components in CSA are anhydrous calcium sulfoaluminate, dicalcium silicate and gypsum. CSA cements do not work like Portland and the lime in CSA is bonded and not free. Because of this, the alkalinity is very low and pozzolans do not work well with CSA. CSA will work with retardants, accelerators and plasticizers It will also work well with integral pigments and topical stains including acid stains.. Under normal conditions CSA cements can set as fast as 25 minutes and compressive strength can exceed 5000 psi in less than 24 hours. The greatest benefits are realized when 100% of the Portland is replaced with CSA and no pozzolans are used. Replacing 20% of CSA with VCAS has actually been shown to lower the compressive strength of test cylinders by 30%! Because CSA uses 50% more water for the hydration process and because of early set time, shrinkage characteristics are greatly reduced.CSA is available in white as well as grey. The cost is a little over double what you would pay for Portland. It is currently available from two US companies, Ultimax and CTS Cement Manufacturing and then redistributed again under other names such as “Rapid Set”.
D
Diacalcium Silicate
Belite ; the second main compound in cement.
Diatomaceous Earth
A friable earthy material composed of nearly hydrous amorphous silica (opal) and consisting essentially of the frustules of the microscopic plants called diatoms.
Drop In Sink
A sink that has a rim that fits over the countertop, also known as a top mount or self rimming.
E
Edge Return
A countertop edge that is thicker than the rest of the slab, to give the appearance of a thicker slab.
Epoxy Sealer
A 2 component system that reacts when mixed to form a hard durable sealer. Can be UV sensitive and are not heat resistant. Tends to be shiny, thick and look like plastic.
Ettringite
Needle like crystalline compound produced by the reaction of C3A, gypsum, and water within a Portland cement concrete.
Expansion Joint
A separation provided between adjoining parts of a structure to allow movement.
Expansive Cement
A modified Portland cement that when mixed with water forms a paste which purposely increases in volume during the early hardening period, to a significantly greater degree than pastes containing ordinary Portland cement.
F
False Set
Early stiffening that generally occurs within the first few minutes after mixing Portland cement with water, without evolution of much heat. Workability can be restored when the material is re mixed.
Ferrocement
One or more layers of steel wire armature or reinforcement encased in Portland cement mortar creating a thin-section composite material. Ferrocement is a composite material which is used in building or sculpture with cement, sand, water and wire or mesh material—often called a thin shell in North America. Ferrocement has great strength and economy. It is fireproof, earthquake safe and does not rust, rot or blow down in storms. It has a broad range of applications which include home building, creating sculptures, repair of existing artifacts and building boats and ships.
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.
Final Set
An arbitrary measure of the time at which paste, mortar, or concrete is able to resist penetration by a standard weighted test needle.
Fineness
A measure of the degree of subdivision of a finely ground material (powder), such as cement. The parameter used is specific surface area, determined wither by turbidmetry (Wagner) or air-permeability measurements.
Flash Set
Very rapid stiffening that can occur within minutes when Portland cement is mixed with water. Considerable heat is evolved and workability cannot be restored by further mixing without the addition of water.
Flexural strength
The ability of solids to resist bending.
Fly Ash
The finely divided residue resulting from the combustion of ground or powdered coal and which is transported from the firebox through the boiler by flue gases.
Free Lime
Calcium oxide (CaO) as in clinker and cement which has not combined with SiO2, Al2O3, or Fe2O3 during the burning process, usually because of under burning, insufficient grinding of the raw mixture, or the presence of traces of inhibitors.
Freeze Thaw Resistance
Ability of concrete to withstand cycles of freezing and thawing. Typically an air entrainment admixture is used to achieve this ability.
G
GFRC
*This definition is as produced by a PCI certified plant.*
A sprayed cement deposit with an absolute minimum of 4% AR glass fiber by weight of total mix with a design thickness of ½ inch.
GFRC Premix
A process of mixing cement, sand, and AR glass fibers into a mortar. Applications include spraying, casting, pressed, slip formed and extruded.
Grading
Size distribution of aggregate particles, determined by separation with standard screen sieves.
Granulated Blast Furnace Slag
Is glassy granular material formed when molten blast-furnace slag is rapidly chilled by immersion in water.
GRC
Glass reinforced concrete is synonymous with glass fiber reinforced concrete.
Grout
A mixture of cementacious material with or without aggregate or admixtures. Usually sold as “shrinking” or “non shrinking” and “sanded” or “non sanded”
Gunite
A dry high pressure air applied to concrete mix.
H
Heat of Hydration
Is the heat that is generated by the reaction when water is mixed with hydraulic cement
High Strength Concrete
Concrete design strength of at least 10,000 psi.
Honeycomb
A term used to describe the failure of mortar to completely surround course aggregates in concrete, leaving voids between them.
Hydrated Lime
Dry powder obtained by treating quicklime with a sufficient amount of water to satisfy its chemical affinity for water. The process takes place in a hydrator, which combines the dry, pebbly quicklime with a carefully controlled amount of water. In their process, they add 23% water to quicklime", they told us. This produces Type S hydrated lime, Ca(OH)2/Mg(OH)2, calcium hydroxide/magnesium hydroxide. All of the water is chemically combined with the quicklime, so the product remains a "dry", free-flowing powder.
Hydration
Is the chemical reaction between hydraulic cement and water. It is an inorganic chemical reaction where water is added to the crystal structure of a mineral, usually creating a new mineral called a hydrate. Resulting strength producing properties are formed.
I
ICF
Insulated Concrete Forms
Initial Set
A measure of time at which concrete can resist to a given degree the penetration of a weighted test needle.
Integral Sink
A sink made out of the same material as the countertop and forms a continuous surface with the whole piece.
Isolation Joint
A separation that allows adjoining parts of a structure to move freely to one another, both horizontally and vertically.
K
Knockout
A rubber, wood or foam shape placed in a form where will be a hole in the countertop. Typically used for drains.
L
Lightweight Aggregate
Low density aggregate used to produce lightweight concrete. Could include expanded or sintered clay, slate, diatomaceous shale, perlite, vermiculite, or slag; natural pumice, scoria, volcanic cinders, tuff, or diatomite; sintered fly ash or industrial cinders.
Lime
General term that includes the various chemical and physical forms of quicklime, hydrated lime, and hydraulic lime. It may be high-calcium, magnesium or dolomitic.
M
Matrix
The cement and water paste that fills voids between aggregates and glass fibers.
Melamine
Particle board coated with a plastic material. Used in forming concrete countertops because of its smoothness and easy fabricating.
Metakaolin
Refined Kaolin clay that is fires or calcinized under carefully controlled conditions to create an amorphous aluminosilicate pozzolan that consumes calcium hydroxide (lime) byproducts produced during cement hydration. This results in increased compressive strength due to increased lime content. Used as a 10%-20% replacement for cement.
Microspheres (cenoshperes)
Very fine, lightweight hollow ceramic spheres that are chemically identical to fly ash but too large to offer any significant pozzolanic reactivity. Used as a replacement for sand for lightweight concrete or to modify the consistency of the concrete, making it stiffer and less sticky.
Moist Air Curing
Curing with moist air, no less than 95% humidity and at a temperature of approximately 75 degrees F.
Mortar
Mixture of cementacious materials, fine aggregate and water, which may contain admixtures, and is usually used to bond masonry units.
N
Natural Pozzolan
Either a natural, raw or natural calcined material that has pozzolanic properties.Example: Volcanic ash, pumicite, opaline chertand shales, tuffs and some diatomaceous earths.
Normal Weight Concrete
A class of concrete made with normal density aggregates, usually crushed stone or gravel, having a density of approx 2400 kg/ms or 150 lb./ft3.
No Slump Concrete
Concrete having a slump of less than ¼”.
O
Overlay
Concrete overlays date to the 1960s when chemical engineers from some of the larger, well known chemical companies began to experiment with acrylic paint resins as modifiers for cement and sand mixes. The result was a thin cementitious topping material that would adhere to concrete surfaces and provide a newly resurfaced coating to restore the worn surface. Concrete overlays lacked the long term performance characteristics of acrylic resins. Acrylic resins provided good UV resistance, but lacked long term water resistance and adhesion characteristics needed to provide a long term and permanent solution.
P
Paste
The fraction of concrete consisting of powder, water and air, plus an admixture if applicable. No aggregates
Passing Ability
The ability of fresh concrete to flow through tight openings, such as spaces between steel reinforcement without blocking or segregation.
Penetrating Sealer
A sealer with the ability to penetrate into the surface of concrete to increase water repellency and resist stains.
Permeability
The ability of concrete to pass fluids or gasses.
Pervious Concrete (no fines or porous concrete)
Concrete containing insufficient fines or no fines at all to fill the voids between aggregate particles in the mixture. The coarse aggregate particles are coated with a cement and water paste to bond the particles at their contact points. The resulting concrete contains a interconnected pore system allowing liquid to drain through.
pH
Chemical symbol representing the acidity scale. Less than 7 represents acidity and greater than 7 is high alkalinity.
Pigment
A finely ground material or synthetic particle that constitutes the opacity or color of a coating or topping.
Plastic Cement
Special hydraulic cement product manufactured usually for plaster or stucco applications. One or more inorganic plasticizing agents are interground or blended with the cement to increase the workability and molding characteristics.
Plasticity
Measure the workability and mold ability of freshly mixed cement paste, concrete, grout, mortar or plaster.
Polymer
An additive that is mixed into concrete mix that changes the durability or adhesion characteristics of the final product.
Popout
Shallow depression in a concrete surface resulting from the breaking away of pieces of concrete due to internal pressure.
Portland blast-furnace slag cement
Hydraulic cement consisting of: 1. an intimately interground mixture of Portland cement clinker and granulated blast-furnace slag, 2. an intimate and uniform blend of Portland cement and fine granulated blast-furnace slag with or without additions.
Pozzolan
A siliceous or siliceous and aluminous materials, like fly ash or silica fume, which in itself possess little or no cementitious value but which will , in finely divided form and in the presence of moisture , chemically react with calcium hydroxide at ordinary temperatures to form stronger compounds possessing cementitious properties.
R
Reactive-powder concrete
High strength, low water and low-porosity concrete with a high silica content and aggregate less than 0.3 mm in size.
Ready Mixed Concrete
Concrete manufactured for delivery to a location in a fresh state.
Reinforced Concrete
A structural composite of concrete with embedded tendons designed to carry tensile loads. These can be made of metal rods such as rebar or metal screen, wire or fibers.
Retarder
An admixture that delays the set-time of concrete.
S
Scaling
Disintegration and flaking of a hardened concrete surface frequently die to repeated freeze and thaw cycles and application of deicing chemicals.
Segregation
The separation of aggregates and mortar in fresh concrete.
Set
Describes the degree to which fresh concrete has lost its plasticity and gained hardness.
Silica Fume
Very fine noncrystalline silica which is a by product from the production of silicon and ferrosilicon alloys in an electric arc furnace and is used as a pozzolan.
Shotcrete
Concrete that is applied with high pressured air, sprayed onto a surface. Also known as Gunite
Slump
Used to measure the consistency of concrete. To perform a slump test you must fill an inverted funnel-shaped cone with concrete. When the cone is removed, the concrete “slumps”. The distance is measured to determine the slump.
Slurry
Thin mixture of Portland mixed with several other options of fine powders or sand. Used primarily to fill voids or cracks in cast concrete projects. An example of this would be 2 parts Portland, 2 parts Calcium Carbonate and pigment possibly an Acrylic polymer.
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.
Superplasticizer
An admixture that increases the flowability of a fresh concrete mixture. It is considered a high range water reducer.
Tensile Strengh
The ability of concrete to resist tension forces, or pulling apart forces, expressed in psi.
Tricalcium Aluminate
The main source of aluminum in cement.
Tricalcium Silicate
The main compound of cement. It is responsible for early strength.
U
UBC
Uniform Building Code, published by the International Conference of Building Offickals, Whittier, Ca.
Undermount Sink
A sink that is mounted underneath the countertop.
Urethane
A type of sealer that provides good stain, heat and scratch resistance but is difficult to apply properly and can debond if the concrete surface is not properly prepared.
Unit Weight
Density of fresh concrete or aggregate, normally determined by weighing a known volume of concrete or aggregate.
W
Water Reducer
An 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
A Portland with a low iron content that hydrates to a white paste. Often used in integrally colored concrete to produce brighter color tones.
Workability
That property of freshly mixed concrete that determines the ease and homogeneity with which it can be mixed, placed, compacted and finished.
