The Big Glossary of Cement, Concrete & Hypertufa Terms

Note:  This Glossary was researched, developed & written by the operators of TheGardenArtForum expressly for the benefit & use of its registered members who may freely reproduce it for their own personal use.  It is not, however, to be reproduced in any form or used in any manner, by anyone, for any other purpose without the express written consent of the owners of TheGardenArtForum.
© Copyright 2006 Holland & Tucker All Rights Reserved

Attention Members…If you encounter any incorrect information or wish to have additional terms researched & added to this glossary, please feel free to contact us.

NOTE:  References to “ASTM” indicate formal definitions as specified by the American Society for Testing & Materials.

AAC – Autoclaved Aerated Concrete    Exceptionally lightweight precast concrete product with high thermal qualities and fire resistance. Its mixture contains a combination of Portland cement, sand, lime and gypsum to which water is added to produce a slurry.  Finely powdered aluminum mixed into a paste is then added prior to placement into large forms. The finely powdered aluminum reacts with the alkaline components of the cement and lime producing hydrogen gas.   This gas increases the mixes volume approximately five times and produces a uniformly dispersed cellular structure throughout the mix. Desired shapes are cut and placed into an autoclave, an enclosed pressure chamber, and it is then steam cured at about 3500 F.  When fully cured, its final volume consists of approximately 80% air voids and it weighs about one-fifth an equal volume of standard concrete.  With a typical weight of about 30 pounds per cubic foot, AAC will readily float in water.   Also commonly and incorrectly referred to as Foamed Concrete or Cellular Concrete, neither of which is necessarily autoclaved.  NOTE:  AAC is an excellent material for use as a base or armature for sculpting cementitious materials.  It can be easily cut and shaped using ordinary hand tools such a wood saw, rasps and even woodworking chisels.

Abrasion Resistance    The ability of a surface to resist being worn down by friction or rubbing process.

Absolute Volume    The measured volume of any dry ingredient in its absolute solid state and free of voids between any individual particles.   For fluids it is the cubic content actually occupied. For concrete, the actual volume occupied by the various ingredients is determined by dividing the weight of each ingredient in pounds, by its specific gravity and multiplying it times the weight of one cubic foot of water in pounds. For Example: The Absolute Volume of one sack of cement can be found as follows: 94 pounds(wt. of 1 sack of cement) ÷ 3.15 (specific gravity of cement) X 62.4(wt. in pounds of 1 cf of water) = 0.478 cubic feet

Absorbed Moisture    Any moisture that is mechanically held within a given material. In aggregates, for example, any water it contains that is not available to become part of the mixing water is referred to as “absorbed” water.

Absorption    The process by which water is absorbed or taken into another material. The amount of water absorbed by any given material is generally expressed as a percentage of the dry weight of that material.

Accelerator    A chemical admixture that, when added to concrete, mortar, or grout, increases its rate of hydration, which shortens the time of set and increases the rate at which hardening or strength development takes place.  (Also see “Retarder”)

Acid Etch Color or “Stains”   The products employed for use on any cementitious-based mixture whereby it may be rendered in color after curing.  It is accomplished by means of the application of specially formulated acids containing various mineral salts that chemically react with the free lime in the cement producing a wide range of permanent colors that lightly penetrate into the surface.  “Stain” is therefore somewhat of a misnomer.   NOTE:  For a detailed comparison of many of the colorant options available, see the separate pages on this site titled “Cement Color Products Reference Guides“…colorant-guides.pdf

Adiabatic Curing    The maintenance of ambient conditions during the setting and hardening of concrete so that heat is neither lost to nor gained from the environment surrounding the concrete.

Admix or Admixture     Any material other than water, aggregates and Portland cement that is used as an ingredient of concrete and is added to the batch before or during the mixing operation.  Generally incorporated to produce specific results such as freeze/thaw resistance, increased density, accelerated or retarded set, etc.

The “official” categories are as follows:

ASTM C 494, “Standard Specification for Chemical
Admixtures for Concrete,” classifies admixtures into seven
types as follows:

Type A Water-reducing admixtures;
Type B Retarding admixtures; (slows the set time)
Type C Accelerating admixtures; (quickens the set time)
Type D Water-reducing and retarding admixture;
Type E Water-reducing and accelerating admixtures;
Type F Water-reducing, high-range, admixtures; and
Type G Water-reducing, high-range, and retarding

Adsorption Water    Water held on the surface of a material either by physical and/or chemical forces.

Aggregates    Those particulate materials added to cementitious mixtures primarily as inert and non-reactive “fillers” such as sand, gravel & rock.  Typically size-graded based on industry standard “screens” or “sieves”. (Also See “Microaggregates”, “Fines” & “Screens”)
The following are the standard ASTM & WIDOT definitions of various commonly used aggregates:

Mason’s Sand – classified as a fine aggregate meeting ASTM C 144 for masonry mortar. It is washed and double screened to be a finer sand and is lighter in color than torpedo sand.

USES: mortar mix for masons, bunker sand for golf courses, beach sand, volleyball courts, under vinyl swimming pool liners.

Torpedo Sand – classified as a fine aggregate with the largest particle size less then 3/8″. Yellowish, beige in color, it is washed and screened. Meets ASTM C 33 sand for concrete.

Concrete Gravel – a pre-mix of torpedo sand and #6 stone. With the addition of cement, these are the principal materials used for producing most site mixed concrete.  It is designed for smaller projects where the delivery of ready mixed concrete is not practical and the user can mix their own small batches of concrete.

USES: farm barnyard patching, small footing projects, fence post anchoring.

Pea Gravel – classified as a coarse aggregate meeting ASTM C 33 Size No. 8. It is light in color, a blend of beige, tan, white, gray and small amounts of black and red stones. It is crushed, washed and screened to a size less than 3/8″ with no fines.

USES: backfill along foundation walls, concrete subgrade (requires no compactive effort), pipe bedding, dog runs, underneath golf course greens and in ready-mixed concrete for exposed aggregate concrete or thin coat overlays.

#6 Stone – classified as a coarse aggregate meeting ASTM C 33, Size No. 67. It is light in color, a blend of beige, tan, white, gray and small amounts of black and red stones. It is crushed, washed and screened to a size less than 3/4″ with no fines.

USES: principal stone in ready-mixed concrete, drain tile bedding, backfill for foundation walls or slabs and sometimes use in landscaping or in septic system construction.

#8 Stone – classified as a coarse aggregate meeting ASTM C 33, Size No. 4. It is identical in color to #6 stone but is crushed, washed and screened to a size less than 1 1/2″.

USES: septic system drain fields, drain tile cover, landscaping decorative stone and sometimes in ready-mixed concrete.

Structural fill/Bedding Sand – meets WIDOT Section 209 and 210, granular backfill, Grade 2 and culvert pipe bedding. It is screened, coarse and unwashed and is very compactable.

USES: foundation backfill or under slabs, under brick pavers, etc.

Boulders – multi-colored, screened from 8″ to 18″ in size, sometimes called field stone.

USES: primarily used in landscaping for retaining walls, rip rap, borders, etc.

Limestone Base Rock – 3″ crushed and screened limestone with a minimal amount of binder fines. It can be white, gray, yellow or have a reddish tint.

USES: sub-base support under roads, driveways, foundations or any area that requires stabilization, also used in erosion control for spillways.

Road Gravel – meets WIDOT Grade 1 and Grade 2. It is 3/4″ and less crushed, fractured stones mixed with binder fines.

USES: gravel road top coat, gravel shoulders, backfill, slab subgrade, gravel driveways.

Crushed Recycled Mix – recycled concrete is an excellent alternative to road gravel, the concrete is crushed to 3/4″ size. This product meets WIDOT Grade 2 road gravel. Recycled concrete has less tendency to erosion.

USES: wherever road gravel can be used, is very compactable with water which is often added before compaction.

Yellow Limestone Traffic Bond or White Limestone Traffic Bond – sometimes referred to as Grade #9, 3/4″ minus to 5/8″ minus crushed stone mixed with binder fines. Colors range from light tan to yellow. It is less erodible than road gravel. If color is a concern, white is more expensive then yellow.

USES: It is best used in residential driveways where paving will not take place.

Air Content    The amount of air trapped or entrained in concrete or mortar, exclusive of pore space in aggregate particles.  It is generally expressed as a percentage of total volume of the concrete or mortar.

Air Entraining Agent     An additive for hydraulic cement or an admixture for concrete or mortar used to intentionally entrain air in the form uniformly distributed minute bubbles which remain in the mixture throughout the full set & cure of the finished product.  Primarily used for controlling freeze/thaw damage, it also yields a lighter weight product than non-air entrained mixes.  (Also see “Concrete, Air Entrained”)

Alkali-Aggregate Reaction     Archaic term for Alkali-Silica Reactivity (ASR-see below).

Alkali-Silica Reactivity  (ASR)    The reaction of aggregates, which contain some form of silica or carbonates with sodium oxides or potassium oxides in cement that cause expansion, cracking or popouts in concrete.

Aluminous Cement     A hydraulic cement whose principal constituents, unlike those of Portland cement are calcium aluminates, instead of calcium silicates.  (Also see “Calcium Aluminate Cement”)

Armature    A term used in “additive” sculpting to describe the framework or “skeleton” used to support and build up a shape upon.  Whether used with clay, plaster, cement or any other material,  the armature must be constructed of a material compatible with the material to be applied and sturdy enough to support its weight.

Aspdin, Joseph ( 1778 – 1855)  The English stonemason who invented and patented the processes for manufacturing Portland Cement on October 21, 1824 (British Patent BP 5022 entitled An Improvement in the Mode of Producing an Artificial Stone).  He named his new product after the natural, light gray stone quarried near the English city of the same name.  Portland Cement was the first true hydraulic cement to be mass produced to consistent standards since the formulation for Roman Cement was lost with the fall of the empire.  It remains today, the most widely used building material on Earth.

Autoclave     A chamber in which steam and high pressure are produced. Used in the curing of concrete products and in the testing of hydraulic cement.

Bag (of cement – See “Sack”)

Barrel (of cement)     A unit of weight for cement: 376 Ibs. net and the equivalent to 4 US bags of Portland cement.

Bendable Conrete (See “Concrete, Bendable”,  aka “ECC” for “Engineered Cementitious Composite”)

Blaine Fineness   The measure of the fineness of granular materials such as cement and pozzolans, expressed as a total surface area in square centimeters per gram.

Blast Furnace Slag   Non-metallic waste by-product produced during the manufacture of pig iron that consists primarily of lime, silica, and alumina.  It is used in the manufacture of Portland blast furnace slag cement as well as an aggregate in lightweight concrete.

Bleeding   A type of segregation in which some of the water in a mixture rises to the surface of freshly placed concrete. Sometimes referred to as water gain.

Bond    The adhesion between concrete or mortar and reinforcements or other surfaces. Also the adhesion between cement paste and aggregates.

Bonding Agents    Any of the family of adhesives employed to secure concrete or mortar to reinforcements or other surfaces.  Commonly used to adhere new concrete to old or existing concrete when resurfacing or repairing.  Can be used as a surface treatment, admix or both.

Bush-hammer   A percussive hammer with rows of pyramid-shaped points used to roughen, profile or texture a concrete surface.

Calcareous    Containing calcium carbonate or (less commonly) the element calcium.

Calcine    To alter a composition or its physical state by heating it to a specific temperature for a specific length of time.

Calcium Aluminate Cement    These may also be termed ‘Ciment Fondu’ and used to be called ‘high alumina cements.’ They are made from lime or limestone mixed with bauxite (aluminum ore) or other high-alumina material. Commonly used in refractory concrete for high-temperature applications.  (Also see “Ciment Fondu”)

Capillarity   The action in which a liquid will migrate vertically through a material.

Capillary Space    Any space within cement pastes that are not occupied by anhydrous cement or cement gel.  Air bubbles, whether entrained or entrapped, are not considered as being part of the cement paste.

A. The Reaction between the products of Portland cement (soluble calcium hydroxides), water and carbon dioxide that produces insoluble calcium carbonate (also known as efflorescence).
B. The soft, white, chalky surface that appears on freshly placed, unhardened concrete.   It is often caused by carbon dioxide from unvented heaters or gasoline powered equipment used in enclosed spaces.
C. The dense, impermeable top layer of the surface of concrete resulting from a  surface reaction to carbon dioxide.
D.  The slight shrinkage that occurs in concrete in reaction to carbon dioxide.
This reaction improves long-term chemical stability and many concrete products are deliberately exposed to carbon dioxide (after reaching 80% strength) to induce this shrinkage which makes the product more dimensionally stable. This process reduces future drying shrinkage by as much as 30%.

Cellular Concrete    A lightweight product consisting of Portland cement, cement-pozzolan, cement sand, lime-pozzolan, or lime-sand pastes, or pastes that contain blends of these ingredients and which also have a homogeneous cell structure produced by gas-forming chemicals or foaming agents. Many cellular concretes produced in this fashion also employ autoclave curing.

Cement    A building material manufactured by grinding calcined limestone and clay to a fine powder, which can be mixed with water and poured to set as a solid mass or used as an ingredient in making mortar or concrete.

Cement, High Early Strength – (Type HE)   High Early Strength Cement. Develops its’ strength more rapidly (not to be confused with rapid setting time). Well suited to the pre-cast concrete industry & any other structures where early strength for removing formwork is necessary.  Otherwise referred to as “Type III”.  (Also see “Cement Types” chart below)

Cement Content   The quantity of cement contained in a given volume of concrete or mortar. This measure is generally expressed in terms of pounds, barrels, or bags per cubic yard of concrete or mortar.

Cement Paste   The colloidal (glue-like) material which constitutes the majority of the porous mass of which hydrated cement paste is composed.  The plastic combination of cement & water that supplies the cementing action in concrete.

Cement, Portland    (ASTM C150) A powdery substance produced by burning a mixture of clay and limestone at high temperatures.  This results in lumps called “clinkers” which are then ground into a fine powder that consists of hydraulic calcium silicates. (For non-Portland cements, see “Aluminous Cement”)

Cement, Rapid Setting    Not to be confused with High Early Strength Cement (See Above), this product simply achieves very rapid set times.  Strength gain is somewhat faster than conventional Portland Cement, but not as fast as High Early Strength.  Also not to be confused with the Brand Names “Rapid Set” or ” Quikrete”, two companies that produce a wide range of special purpose cement & concrete products.

Cement Types, Portland    As officially defined by the US Department of Transportation:  

                 Portland Cement Types & Their Uses

Cement Type Use
I General purpose cement, when there are no extenuating conditions
II Aids in providing moderate resistance to sulfate attack
III When high-early strength is required (Also known as Type HE)
IV When a low heat of hydration is desired (in massive structures)
V When high sulfate resistance is required
IA A type I cement containing an integral air-entraining agent
IIA A type II cement containing an integral air-entraining agent
IIIA A type III cement containing an integral air-entraining agent

Courtesy United States Department of Transportation – Federal Highway Administration

Cementitious    Possessing cement-like, cementing, or bonding properties. Any material or substance that produces similar bonding or cement-like properties.

Chair(s)    Small devices used in concrete formwork to support the internal reinforcing steel while the concrete is in a plastic or fluid state.

Change of State    The alteration of physical properties as well as the processes themselves that materials go through when changing from gases to liquids, to solids or the reverse and inclusive of various “semi” states in-between.  Example: Water. When the steam cools it condenses and moves from a gaseous state into a liquid state.  Reduce the temperature further and it goes from the liquid state to a solid state…ice.  Concrete & mortar go through a change of state that is generally considered as transitioning from a plastic (semi-liquid state) to a solid as a result of the chemical processes involved.


Ciment Fondu   The registered tradename for the world’s first commercially manufactured calcium aluminate cement, patented by J. Bied Lafarge in 1908.   Dark brown or dark gray in color, this high alumina (40%) binder is resistant to both sulfate attack & high temperatures making it the product of choice for refractory and chemical environment applications.  It is a very rapid setting product that reportedly achieves full strength within 24 hours.  It is also widely used by artists & sculptors for a wide range of applications including casting, sculpting & mold-making.

Coarse Aggregate    Any naturally occurring, processed or manufactured, inorganic particles which meet standardized gradation or size range requirements, the smallest size of which shall be retained by a No. 4 (4.76 mm) sieve.

Coefficient of Thermal Expansion    The change in unit length per degree of change in temperature.

Cold Joint    The visible delineation that occurs when concrete placement is delayed and the concrete already in place hardens prior to the fresh placement of concrete against it.

Colloidal     A gel-like mass which does not allow the transfer of ions

Color Hardener    A blend of cementitious materials, special mineral aggregates (often including emery & quartz) and integral oxide or synthetic colorants that is used as a surface finish to resist wear in high-traffic areas, enhance traction and/or for decorative purposes.  Typically applied to freshly placed concrete by means of the “dry-shake” method up to 1/8th inch thick.  Often combined with a dry or liquid release when used for stamping textures or patterns into concrete.  NOTE:  For a detailed comparison of many of the colorant options available, see the separate pages on this site titled “Cement Color Products Reference Guides“…colorant-guides.pdf

Color Release    A special purpose natural oxide or synthetic colorant designed to also act as a mold release when stamping patterns into freshly placed concrete.  Available as a spray on liquid or dry shake powder in a wide range of colors including semi-transparent “antiquing” products that enhance the relief & texture of the pattern.  NOTE:  For a detailed comparison of many of the colorant options available, see the separate pages on this site titled “Cement Color Products Reference Guides“…colorant-guides.pdf

Compressive Strength     A concrete or mortar specimen’s measured resistance to axial loading expressed as pounds per square inch {psi) of cross-sectional area. The maximum compressive stress which the material is capable of sustaining.

Concrete    A mixture of cement (usually Portland), various aggregate fillers (sand, gravel, rock) and water which chemically hardens into an insoluble monolithic composite.  The most common formulation is often referred to as a “standard 1-2-3 mix” and consists of One part Cement + Two parts Sand + Three parts Gravel (or Stone).

Concrete, Air Entrained    Air-entrained concrete is produced through the use of specially formulated air-entraining Portland cement, or by the introduction of air-entraining agents. The amount of entrained air is usually between 4 percent & 7 percent of the volume of the concrete, but may be varied as required by special conditions.  It contains billions of uniformly distributed microscopic air cells per cubic foot. These air pockets act to relieve internal pressure on the concrete by providing chambers for water to expand into when it freezes.  Typically runs 10 to 15% lighter than conventional concrete.  (Also see “Air Entraining Agent”)

Concrete, Bendable    Properly known as “Engineered Cementitious Composite” or “ECC”.  Arguably the most important single advance in the field since Roman Concrete.  A relatively simple formulation of common cementitious compounds, admixtures & additives that yields an end product that works, handles, sets, cures & looks like conventional concrete, yet is extraordinarily ductile and has the capacity to flex or deflect an extreme amount without failing.  ECC is said to be 500 times more resistant to cracking and also 40% lighter than conventional concrete.  Developed by Professor Victor C. Li of the University of Michigan, it is a mixture of ordinary Portland cement, water, fine sand, silica powder, fly ash, PVA fibers & superplasticizer ( exact proportions unspecified at this time, except that the fibers constitute 2% or less).  According to its developers, it’s unique properties are attributed to  the fact that…”under excessive strain, the ECC concrete bends because the distinctively coated matrix of fibers in the cement is allowed to slide within the cement.”

Concrete, Complex     Similar to Basic Concrete but with the addition of various chemical modifiers, admixtures, additives and/or special purpose aggregates.

Concrete, Densified     Any concrete that has been specifically formulated to achieve a density greater than that of Basic Concrete.  Generally accomplished with the addition of micro-aggregates such as fly ash and/or polymer admixtures.  Such mixtures result in a product that has reduced porosity and is consequently less susceptible to penetration by fluids.

Concrete, Engineered    Any concrete formulated expressly to meet a specific set of pre-determined technical standards or performance requirements.

Concrete, Lightweight   Any concrete that incorporates any of a variety of weight reducing aggregates (such as perlite or vermiculite), or has been mixed or processed with components that generate controlled entrained air bubbles, specifically for the purpose of creating an end product whose weight is less than that of conventional concrete (approximately 150 pounds per cubic foot).

Concrete Mix Ratios   The numerical values of basic concrete mix components as expressed in relative parts.  These relative values should always be expressed or stated in the following order;  Cement first, then Sand, then Gravel (or Stone).  Example:  A “standard 1-2-3” mix consists of One part Cement + Two parts Sand + Three parts Gravel (or Stone).

Concrete, Refractory    Any concrete formulated specifically to achieve thermally resistant or insulating properties and suitable for use at high temperatures. Calcium-Aluminate cement and refractory aggregates are normally used for the manufacture of this product.

Concrete Sealers   A group of liquid compounds specifically designed for the purpose of protecting cured concrete or any cement-based medium from surface wear or the intrusion of damaging environmental contaminants.  They are also commonly used to create a specific surface treatment and enhance the coloration of the substrate to which it is applied.  They are commonly available in two basic formulations:
1.  Water-Based Film Forming Sealants
2.  Solvent-Based Penetrating Sealants
The proper formulation choice depends on a range of appearance & performance factors that must be determined by the applicator. (For a more thorough treatise on these materials see the following information in the TGAF Technical Library:  Concrete Sealer 101 for Artists & Crafters

Condensation     The moisture formed when a moisture-laden gas comes in contact with a cooler surface causing a change of state from gaseous to liquid.

Consistency    The degree of plasticity demonstrated by fresh concrete or mortar. The standard measures of consistency are “slump” for concrete, and “flow” for mortar. (Also see “Slump”)

Consolidation   The compaction accomplished (usually) by vibration, of newly placed concrete.   Generally done to eliminate excess trapped air and/or ensure the mix fully conforms to the mold or form.  Also aids in forming bonds with any embedded parts or reinforcement.

Cure   The method by which sufficient internal humidity and proper temperature are maintained to ensure that the hydration process of the cement within the freshly placed concrete or mortar is uninterrupted allowing full and proper hardening to take place.

Cure, 28 Day or 28 Day Strength   The arbitrary period chosen as the standardized engineering reference point at which hydration is considered adequate for a given concrete mix to have achieved 100% of its design strength.   Concrete gains strength very rapidly at first, then the process slows proportionally over time.  Typical strength gain is about 45% in 3 days, 75% in 7 days and 100% of design strength in 28 days.  Note that this standard refers only to “design” strength. Concrete will actually continue to gain strength and further harden for an indeterminate period spanning decades or possibly even centuries making the measurement of its ultimate strength impractical.  This standard point of reference measures what is believed to be approximately 90% of concretes final, ultimate strength.

Curing   The processes involved in or the period of time during which hydration is taking place.

Densified Concrete (See “Concrete, Densified”)

Dispersing Agent    An admixture that increases the fluidity of pastes, mortars, or concretes by reducing interparticle attraction.

Drying Shrinkage   The decrease in volume that occurs while concrete is drying.

Durability    The general measure of a particular concrete formulations ability to resist weathering, chemicals, and abrasion.

ECC – Engineered Cementitious Composite  aka “Bendable Concrete” (Also See “Concrete, Bendable”)

Efflorescence     Deposits of crystalline salts that leach from the concrete as soluble calcium hydroxides and combine with the atmospheric carbon dioxide to form insoluble calcium carbonates.  Usually white in color and appearing on the surfaces of masonry, stucco or concrete.

Entrained Air   Microscopic air bubbles that are intentionally incorporated into concrete or mortar to achieve specific results.  Originally developed to improve freeze/thaw resistance in cold climates, it is often employed today to reduce weight or improve workability.  (Also see “Air Entrainment”)

Entrapped Air    Air which is not intentionally entrained in concrete & mortar. Larger and more irregularly distributed than entrained air bubbles, they can seriously weaken a structure and cause unsightly surface irregularities.

False Set    The rapid development of apparent rigidity in mixed Portland cement paste, mortar, or concrete that is not accompanied by the development of any significant heat. This false rigidity can be disregarded and plasticity restored by means of additional mixing without the addition of water.

Faux BoisFerrocement   (Faux Bois; From French for “False Wood”, Pronounced Foe-‘Bwahand Ferrocement; any cement-based material such as concrete, that is internally reinforced with steel)
The school of arts & crafts dedicated to imitating either wood or wood grains in various mediums.  While wood finishers routinely forge the grain, colors, and appearance of finer woods like Mahogany, Rosewood and Oak onto lesser woods such as pine, Ferrocement Faux Bois utilizes concrete, mortar and neat Portland cement paste to sculpt three-dimensional representations of trees, wood and wooden objects onto steel frames or armatures.  It was very popular and widespread from the mid-1800’s up to about the 1940s but has become an almost lost art with the passing of the masters of the craft who never recorded or otherwise divulged their trade secrets.  The vast majority of the now antique works that remain are garden art objects such as planters, birdbaths, and outdoor furniture.  Today they are highly sought after by avid collectors and command serious prices.

The Spanish term for the style that was developed in Mexico during that time is “El Trabajo Rustico” (The Rustic Work).  Without question, the very finest work ever executed was in this style by an artisan named Dionisio Rodrigues (NOTE:  Mr. Rodrigues applied two different spellings of his name to his work over the years; one ending with an “s”, which is the old, traditional Spanish version and the other ending with the Anglicized and more common “z”.)  Having moved from Mexico to San Antonio, Texas in the early 1920’s, he produced many remarkable and very large scaled installations all around the United States.  Today, this virtually unknown artist is finally gaining the recognition he deserves with many of his works now officially listed on The National Register of Historic Places.  Further, he currently ranks a close second on that prestigious list to the esteemed Frank Lloyd Wright as having created the greatest number of sites attributable to one person, with numerous other works still up for review.  Below are a couple of examples of highly detailed works sculpted in Ferrocement Faux Bois.

Torii Gate by Dionisio Rodrigues at Brackenridge Park, San Antonio, Texas.

Sculpted bench & table details by D.R. Tucker, Houston, Texas.

Ferrocement    Any cement-based material (generally referring to concrete) that is internally reinforced with some form of ferrous metal (iron, steel).  Such internal structure may or may not be load bearing, but the metal employed must exhibit expansive & contractive properties consistent with the concrete surrounding it.  Patented in 1868 by French gardener Joseph Monier.

Fibers   The general term used to describe a family of additives designed to mechanically strengthen cementitious materials during their early set stages and help prevent early onset cracking.  Widely used in casting & shotcrete where high water/cement ratios can lead to this type of problem.  Available in a range of cut lengths and a variety of materials including different polymers, glasses & metals. NOTE:  Any fibers used in a cementitious mixture must be alkali resistant or they will degrade rapidly. NEWS: Recent discoveries have been made regarding benefits that indicate the potential for increasing post-cure strength as well when employed as part of a ductile enhancing formulation. (Also see “Bendable Concrete”)

Fines or Fine Aggregate   Aggregate passing the 3/8-in. sieve and almost entirely passing the No.4(4.76 mm) sieve and predominantly retained on the No. 200 (74 micron) sieve(ASTM125).  (Also see “Aggregates”)

Fineness Modulus    A standardized index of fineness or coarseness of an aggregate sample. An empirical factor determined by adding total percentages of an aggregate sample retained on each of a specified series of sieves, and dividing the sum by 100. Note: US Standard sieve sizes are used: No. 100, No.50, No. 30, No. 16, No. 8, and No. 4, and 3/8 in., 3/4 in., I in., 2 in., 3 in., and 6 in.

Flash Set    The very rapid development of rigidity in a mixed Portland cement paste, mortar or concrete generally accompanied by the development of considerable heat. This rigidity cannot be dispelled nor can the plasticity be restored.

Flexural Strength    A solids ability to withstand bending.

Fly Ash   The finely divided residue that results from the combustion of ground or powdered coal which is used as a micro-aggregate and additive in concrete. When combined with cement, it becomes a reactive pozzolan that is used to strengthen and densify concrete.  Some modern formulations now replace as much as 60% of the Portland in the mix with fly ash.

Freeze/Thaw Resistance   The ability of a specific cementitious formulation to withstand the effects of repeated freezing & thawing which can destroy most “basic concrete” due to the expansion and contraction forces of moisture within the cured mass.   Air entrainment and/or densification are typically employed to counter these effects and provide their benefit throughout the cured structure.  Sealers can also be beneficial but are limited to simply reducing the migration of any additional moisture into the mass from its outer surfaces.

Fumed Silica    Fumed Silica  (Not to be confused with “Silica Fume”) is a precipitated form of silicon dioxide that is produced chemically, while Silica Fume is a by-product of steel production.  While Fumed Silica is a pozzolanic microaggregate and exhibits benefits similar to Silica Fume, there is less documented study regarding the specific mechanisms and proportion levels.  (Also See “Silica Fume”)

GFRC – Glass Fiber Reinforced Concrete    Concrete reinforced with a high zirconia (16% minimum), alkali-resistant glass fiber.

Gravel, Concrete    A pre-mixed combination of torpedo sand and #6 stone. With the addition of cement, these are the principal ingredients used for producing ready-mixed concrete. This aggregate product is designed primarily for use on smaller projects where the delivery of ready mixed concrete is not practical and allows the user to mix their own small batches of concrete on site.  (Also see “Stone, #6 “)

Gravel, Pea     Classified as a coarse aggregate meeting ASTM C 33 Size No. 8. It is light in color, a blend of beige, tan, white, gray and small amounts of black and red stones. It is crushed, washed and screened to a size less than 3/8″ with no fines.

Grout    A mixture of cement, sand, and water or (2) cement and water: the hardened equivalent of such mixtures.

Gunite   A term often used to designate dry-mix shotcrete. (Also see “Shotcrete”)

Heat of Hydration   The quantity of heat expressed in calories per gram, evolved upon complete hydration of Portland cement at a given temperature.

Hickey or Rebar Hickey    A sturdy steel hand tool for bending rebar. It consists of a handle 30 to 36 inches in length welded to a triangular head bearing three stout posts for leveraging the rebar into various shapes.  The single post on the reverse of the head can be fitted into a hole in a worktop allowing it to rotate around that point for additional leverage & control.

Hydration    Formation of a compound by the union of water with some other substance. In concrete, it is the chemical reaction that occurs when the water and the cement are combined which causes the resulting paste to harden.

Hydration, Set Stages   Below are the commonly used “general rules” observed by most masons for conventional concrete.  NOTE:  These are only approximations and apply only to unmodified mixtures.

Approximate times for the various stages of hydration of modern cement:

1) Initial Set  (after about 45 min): Slightly rigid and ready to be troweled.
2) Final Set  (after about 10 hrs): Hard and ready for forms to be removed.
3) Full Hydration  (after about 7 days): The concrete is said to be “cured”, after which there is no further need to maintain the presence of water in the concrete.
4) Full Strength  (after 28 days): Hydration is considered complete enough (about 95%) that the concrete can now accept the full design loading.  (Also see “Cure, 28 Day)

NOTE:  The hydration process that solidifies & hardens cement paste continues for an indeterminate period that may span 100+ years.  Some authorities believe that it may well continue virtually forever at a continually slowing rate.

Hydraulic Cement    A cement that is capable of setting and hardening under water due to interaction of water and the constituents of the cement (ASTM 219).

Hypertufa    A cement-based formulation designed to reproduce the porous look of the naturally occurring lightweight rock known as Tufa and the resulting products manufactured from this formulation.  Mix ratios vary wildly, but the most common “basic recipe” consists of 1 part Portland cement + 1.5 parts Peat + 1.5 parts Perlite.  The term literally translates as “Fast” or “Beyond” (hyper)…and… “Tufa” (the name for an unusual porous geological formation).  (Also see “Tufa”, “Peat” & “Peat Moss”)

Integral Color   Any such color medium introduced into a cementitious formulation during the mixing stage which permeates the entire mix throughout.   Available in both dry powder and liquid forms, these colorants can also be either natural or synthetic.  Most are based on naturally occurring mineral oxides and are utterly permanent and will not fade or diminish due to environmental exposure  NOTE:  For a detailed comparison of many of the colorant options available, see the separate pages on this site titled “Cement Color Products Reference Guides“…colorant-guides.pdf

Laitance   The weak and non-durable layer of residue consisting of cement, aggregates or impurities that are brought to the surface of over wet concrete by the bleed water.

Liquefaction   The change of state to a liquid.

Masonry Cement   Hydraulic cement manufactured specifically for use in mortars for masonry construction. Typically it is a blend of two or more of the following materials: Portland cement, natural cement, Portland-pozzolan cement, hydraulic lime, slag cement, hydrated lime, pulverized limestone, talc, chalk, pozzolan, clay or gypsum. Some may also include air en-training agent or various admixtures.

Membrane Curing Compounds   A family of chemical compounds expressly designed for the purpose of retaining adequate moisture within concrete, grout & mortar to ensure full and complete hydration.  These compounds are typically sprayed or rolled on and immediately form a thin, vapor resistant membrane that prevents moisture loss through evaporation.  Nearly all of these materials cause discoloration or staining and will prevent the bond of any repairs or permanent coatings that may be needed.  They also require very thorough removal before any post-cure finishing processes, such as painting or acid-etch staining may be accomplished.

Microaggregates   A relatively new term used to identify a category of aggregate material that is significantly smaller than any conventional aggregate such as very fine sand.  These materials have been found to “densify” and add strength to cementitious mixtures by mechanically filling in the voids that would otherwise be present between typical aggregate materials.  Finer grades of Fly Ash, for example, impart this mechanical strength gain separately from and in addition to its benefits as a reactive pozzolan.

Mix Ratios(See “Concrete Mix Ratios”)

Mixer   A piece of equipment used to mix or blend materials used in the production of concrete, grout or mortar.

Mixing Time   For stationary mixers, the mixing time is calculated in minutes from the completion of charging the mixer with water (tempering the mix) until the beginning of discharge.

Monier, Joseph   The French gardener and potter who received the first patent for “Ferrocement” (Concrete,mortar or any cement-based media that is internally reinforced with some form of ferrous metal – generally steel).  Monier routinely cast his own decorative pots and was discouraged by how easily the thin shells were broken.  After a few experiments, he discovered that steel reinforcement complemented the materials naturally high compressive strength by adding its own resistance to flexural forces.  Monier exhibited his invention at the Paris Exposition of 1867. He obtained his first patent on July 16, 1867.

Mortar   A mixture of cement, sand, and water typically used in masonry construction. The mixture may contain masonry cement, or standard Portland cement with lime or other ad-mixtures added to produce greater degrees of plasticity and/or durability.

Neat Cement    Unhydrated hydraulic cement.

Neat Cement Paste    A mixture combining only water and hydraulic cement. No sand or other aggregates are added. However, some admixtures such as superplasticizers and latex fortifiers are typically used in this mix.

No-Fines Concrete     A concrete mixture in which only the coarse gradation (3/8′ to 3/4′ normally) of aggregate issued.

Paste   A mixture consisting of only cement & water that is free of any traditional aggregates or referring to that portion of a mix in which they are present.  (Also see “Neat Cement Paste”)

Peat    A soft brown mass consisting of compressed, partially decomposed mossy vegetation that forms in a water-saturated environment such as bogs & turfs and which has a carbon content of 50%. Dried peat can be burned as fuel and is commonly used as a soil amendment & mulch.

Peat Moss    Any of various pale or ashy mosses of the genus Sphagnum which often grows abundantly in damp boggy or peaty places whose decomposed remains form peat.  One of the principal ingredients in a cementitious product known as Hypertufa which is meant to replicate a porous natural rock type called Tufa (Also See “Peat”, “Tufa”  & “Hypertufa”)

Peeling     A process in which thin flakes of matrix or mortar are broken away from the concrete surface; caused by adherence of surface mortar-to forms as forms are removed or to trowel or float in Portland cement plaster.

Perlite    A fine white aggregate formed by heating and expanding siliceous volcanic glass. Commonly used as a soil amendment and to produce lightweight insulating concrete. (Also See “Hypertufa”)

Plastic   The condition of freshly mixed concrete, mortar or cement-paste that indicates it is workable, readily re-moldable, cohesive and has an ample content of fines & cement but is not over wet.

Plastic Consistency    The state during which concrete, mortar or cement paste can sustain deformation continuously in any direction without rupture.

Plastic Cracking    Cracking that occurs in freshly placed concrete, mortar or paste that occurs while the material is still plastic.

Plastic Shrinkage Cracks   The early onset cracks that occur as a result of rapid & excessive dehydration.  These form in the surface and generally run parallel to one another.  Typically resulting from the lack of compensation for high ambient temperatures and/or air movement over the surface.

Plasticity    Property of freshly mixed concrete, cement paste or mortar which determines its ease of molding or resistance to deformation.

Plasticizer   An admixture formulated to increase the fluidity or flow rate of a concrete mixture, mortar or cement paste without additional water. (Also see “Superplasticizer”)

Popout   Surface pits or craters resulting from the expansive forces associated with foreign materials, contaminants or other unsound aggregates such as wood or glass.

Porosity   The ratio of the volume of voids in the material to the total volume of the material, including the voids, usually expressed as a percentage.

Portland Cement  The man-made hydraulic cementitious product patented in 1824 by English stonemason Josepf Aspdin.  So named for its resemblance to the gray natural stone quarried near the city of the same name.  It is the result of specific manufacturing processes that involve heating a limestone and clay mixture in a kiln and pulverizing and processing the resulting material.

Portland Cement, White    White Portland cement is made from raw materials containing little or no iron or manganese, the substances that give conventional cement its gray color.

Post-Tensioning    A method of reinforcing concrete in which internally placed tendons are tensioned after the concrete has hardened.

Pozzolan    (ASTM C 618) A siliceous, or siliceous and aluminous material, which in itself possesses little or no cementitious value but will, in a finely divided form, such as a powder or liquid and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form permanent, insoluble compounds possessing cementitious properties.

Precast   Any concrete unit, structure or element that is cast and cured in an area other than its final position or place.

Proportioning    The act or process of selecting a particular set of relative proportions of the constituent materials required in order to produce concrete that will meet specific, predetermined design criteria.  Such criteria may include strength, durability, freeze/thaw resistance, economy, workability, flow rate, etc., or any combination of considerations.

Prestressed Concrete   Any concrete into which stresses have been introduced which oppose those that the structural member may be expected to carry during its use.

Pretensioning   The technique in which embedded steel is stressed or tensioned prior to the concrete hardening and is restrained from gaining its unstressed state by virtue of its bond with the concrete when it hardens.

Reactive Aggregate (See “Alkali-Aggregate Reaction”)

Rebar   The common name for the mild steel reinforcing bar specifically designed for use in concrete.  Its metallurgy is engineered to match the thermal expansion & contraction rates of concrete and intended to help overcome concretes inability to carry tensile loading.  It is manufactured in a wide range of diameters and is usually formed with ridges or “cleats” along its surface to aid in adhesion with the cementitious material.   Sizing of rebar is commonly called out based on the number of eighths of an inch that make up the diameter.  Examples:  #3 = 3 eighths(3/8″), #4 = 4 eighths(1/2″), #5 = 5 eighths(5/8″), etc., etc.

Refractory Concrete (See “Concrete, Refractory”)

Reinforced Concrete    Concrete into which some form of mechanical reinforcement has been embedded in such a way that the two materials act together to resist external forces.  (Also see “Ferroconcrete” & “GFRC” )

Retardation  The process of delaying the set, hardening or strength gain of concrete, mortar or grout.

Retarder   A chemical admixture engineered to extend the setting time of cement paste and therefore any such mixtures as concrete, mortar, or grout.

Retempering   The process of adding additional water to and remixing any concrete that has already begun to stiffen.  Not generally recommended as it usually results in severely weakening the finished product.

Rock Pockets   Areas in which there is an excess of aggregate and a shortage of concrete paste to bind them together.  Generally the result of inadequate mixing, separation during placement, leakage from the mold or form or any combination of the above.

Sack   A standard measured quantity for Portland or air entraining Portland cement equaling 94 Ibs. in the United States and 87.5 Ibs. in Canada. (may be otherwise indicated on the sack for other kinds of cement.)

Sacking   A term that is often used to describe two entirely different processes in masonry.
1.  More properly, a technique for removing or repairing surface defects on concrete by applying a mixture of sand and cement to the moistened surface and then rubbing with a coarse material such as burlap.
2.  Also, the practice of applying wet fabric (such as burlap bags) to the surface of newly placed cement or mortar to help provide a continuous supply of moisture to complete hydration.  The fabric is generally then covered with a non-porous material such as plastic to help prevent loss to evaporation.

Sand    Any fine, granular inorganic material that results from natural or manufacturing processes that reduce rock or stone into fine particles. (ASTM C125) That portion of aggregate passing the No. 4 (4.76 mm) sieve and predominantly retained on the No. 200 (74 microns) sieve.

Sand, Mason’s   Classified as a fine aggregate meeting ASTM C 144 for masonry mortar. It is washed and double screened to be a finer sand and is generally lighter in color than torpedo sand.

Sand, Torpedo   Classified as a fine aggregate with the largest particle size less than 3/8″. Yellowish, beige in color, it is washed and screened.  Meets ASTM C 33 sand for use in concrete.

Sandcasting    The means by which an original piece of work is reproduced from an impression or mold made of compacted, damp sand.  Very likely the oldest form of mass production, it remains today a viable & versatile technique that is used to produce a wide variety of products ranging from industrial steel components to bronze, plaster & cementitious art objects.

Scaling   The flaking, peeling or breaking away of the surface of hardened concrete.

A.  The grade strips or forms which are used as guides for employing a straight edge to bring the surface of concrete to a required level or elevation. (Noun; A Screed)
B.  The act of striking off concrete by this method. (Verb;  To Screed)

Screen or Sieve   A metallic sheet or plate, woven wire cloth, or some such similar device possessing uniformly sized openings used to separate materials according to predetermined size requirements.

Sealer, Concrete     (See “Concrete Sealers”)

Segregation   The tendency of materials to separate from one another based on particle size in handling.

Set   The term used to describe the natural, progressive and observable stiffening of cement paste that results from the process of hydration and which takes place in definable stages.

Initial Set refers to the first phase of stiffening and loss of plasticity.
Final Set is used to describe the attainment of a significant degree of rigidity.

ASTM C 403 identifies initial & final time of set as meeting standardized penetration resistance tests as follows:

Initial Time of Set:  500 psi

Final Time of Set:  4000 psi

(Also see “Hydration; Set Stages”)

Setting Time  The time required for a cement paste, mortar or concrete specimen to attain a specified degree of rigidity when prepared and tested under standardized conditions.

Shotcrete (Also known as Gunite)   Shotcrete is mortar or concrete mix designed to be conveyed through a hose and pneumatically projected at high velocity onto a surface. Shotcrete was invented in the early 1900s by Carl Akeley, a famous American taxidermist, who used it to fill his plaster models of animals.

Sieve (See “Screen”)

Silica Fume     Also known as microsilica, is a byproduct of the reduction of high-purity quartz with coal in electric furnaces in the production of silicon and ferrosilicon alloys.  While the exact nature of its benefits in concrete are the subject of current study, it is known to impart both chemical (pozzolanic) and mechanical (microaggregate) advantages and is a common element of new generation, high performance concrete & mortar formulations.  NOTE:  It is generally agreed that Silica Fume’s strength & permeability benefits are only applicable in very low water/cement ratios requiring the use of a superplasticizer.

The known benefits include:
Reduced concrete permeability
Increased concrete strength
Improved resistance to corrosion
      (Also See “Fumed Silica “)

Slip Form   A prefabricated form designed in such a way that it can be moved, repositioned and reused continuously as concrete is placed.

Slump   A standardized measure of the consistency or plasticity of fresh concrete.  The “degree of Slump” is determined by measuring the amount that a sample settles within a specific time.   A metal cone is filled with sample concrete, placed on a flat, level surface and then removed by lifting vertically.  The difference in height between the specimen and the sample cone measured in inches is the resulting “slump”.

Slump Cone   The metal form used when conducting standardized tests of concrete consistency.  It is in the shape of a truncated cone with a top diameter of 4”, a bottom diameter of 8”, and a height of 12”.

Slurry   A mixture of water and finely divided materials such as Portland cement, slag, or soil in suspension.

Spall    A fragment that is detached from a larger mass of concrete or mortar by pressure,  impact, the action of weather or expansion from within the mass.  The expansion of rusting internal steel reinforcement is a common cause of spalling.

Specific Gravity   The ratio of the weight of a material at a stated temperature to the weight of the same volume of gas-free distilled water at a stated temperature.

Stone, #6    Classified as a coarse aggregate meeting ASTM C 33, Size No. 67.   It is light in color, a blend of beige, tan, white, gray and small amounts of black and red stones. It is crushed, washed & screened to a size of less than 3/4″ with no fines.

Strength, 28 Day   (See “Cure, 28 Day”)

Stucco    A durable mixture of cement, sand, lime and water applied over metal lath or chicken wire or wooden lath used to form the finish covering of walls and ceilings.

Stucco Lath, Metal    A galvanized expanded metal mesh product with diamond-shaped openings designed specifically for the purpose of adhering cementitious & plaster-based materials to various surfaces.  It can be readily nailed or stapled onto wooden surfaces such as walls & ceilings or wired in place on metal frameworks or armatures.

Stucco Lath, Wooden  The traditional narrow boards used to act as a bonding mechanism for cementitious materials & plasters on walls & ceilings.  Spaced and applied in such a way that they stand off of the working surface allowing the finishing material to be pressed through forming a secure mechanical bond. Generally used today in conjunction with chicken wire or metal stucco lath.

Superplasticizer  Any such admixture specifically designed to achieve a high degree of alteration in the working properties of freshly mixed cementitious formulations relative to their water content and which can be employed in either of the following ways:
      A.  To produce a high degree of increased slump or flowability (fluidity) without any increase in the       water/cement ratio…or…
     B.  To allow a mixture to achieve a desired degree of slump or flowability (fluidity) at a reduced water/cement ratio.

Surface Moisture   Any moisture that is retained on the surfaces of aggregate particles which becomes part of the mixing water in a concrete or mortar mix.

Temper   The addition of water and mixing of a cement or mortar mix to initially achieve the specified water to cement ratio  (Also see “Re-tempering”)

Temperature Rise   The total increase in concrete temperature caused by heat of hydration and any heat from other sources.

Transit-Mixed Concrete   Concrete that is produced from a central-batching plant where the materials are proportioned and placed into truck mixers for mixing either en route to or at the job site.

Tufa   The name for an unusual and naturally occurring geological formation that is the basis for the production of a man-made cementitious mixture known as “Hypertufa” meant to mimic it’s lightweight and porous properties.  NOTE: The rock type “tufa” is commonly confused in name by laypersons with the rock type “tuff”, which is a rock formed from welded volcanic ash. These rocks are nothing like each other.  Tufa is a rough, thick, rock-like calcium carbonate deposit that forms by precipitation from bodies of water with a high dissolved calcium content. (Also see “Hypertufa”)

Ultimate Strength   The maximum resistance to loads that a structure or member is capable of developing before failure will occur, or with reference to cross sections of members, the largest axial force, shear or moment a structural concrete cross section will support.

Unit Water Content   The quantity of water per unit volume of freshly mixed concrete. Typically expressed in gallons or pounds per cubic yard.  This is the quantity of water upon which the water-cement ratio is based and does not include any water absorbed by aggregates.

Vapor   The gaseous state of a substance which under ordinary conditions exists as a liquid or solid.

Vapor Pressure   The pressure exerted by a vapor.   It is calculated based upon relative humidity and temperature, and the higher the humidity and temperature,  the greater the vapor pressure exerted.

Vaporproof    Any surface or material that totally resists the passage of materials in a gaseous state under pressure.   Any material that is vapor-proof will inherently be waterproof.

Vermiculite    An altered mica that expands greatly at high temperature forming a water-absorbent substance. Commonly used as a base for growing seed plants, an insulating material & as a lightweight aggregate in cementitious mixtures. (Also see “Hypertufa”)

Vibration   The energetic agitation of concrete to aid in its consolidation.  Generally produced by mechanical oscillating devices operating at moderately high frequencies.
A. External vibration employs a device attached to the forms and is particularly useful in the manufacture of molded & precast items.
B. Internal vibration uses a rod-like element which can be inserted into the concrete and is typically used for cast-in-place construction.

Viscosity    The degree of resistance to flow. (Also see “Slump” )

Wagner Fineness    A measure of the fineness of small particulate materials such as Portland cement.  It is expressed as the total surface area in centimeters per gram as determined by the Wagner Turbidimeter apparatus and procedure.

Water/Cement Ratio    The ratio of the amount of water, exclusive only of that absorbed by the aggregates, to the amount of Portland cement in a concrete or mortar mixture.   Preferably expressed as a percentage of water to total cementitious materials by weight in pounds.

Water/Cementitious Ratio    The ratio of water to the total of all cementitious materials in a concrete, mortar, grout or paste mix exclusive only of that absorbed by the aggregates  (NOTE:Portland cement, fly ash & all reactive pozzolans are all considered “cementitious” and must, therefore, be figured into the calculation of “total cementitious materials”.  Aggregates, admixtures & additives do not.).  The ratio is exclusive only of that water absorbed by the aggregates and is preferably expressed as a percentage of water to total cementitious materials by weight in pounds.
Water Gain   (See “Bleeding”)

Waterproof    Any surface or material that is unaffected by and impervious to penetration by water in its liquid state.  (Also see “Vaporproof”)

Water Reducing Admixture    Any such material that either reduces the slump of freshly mixed concrete or mortar without any increase in its water content; or that maintains a given level of workability at a reduced water content, independent and exclusive of the effects of air-entrainment.

Water Reducing Admixture-High Range    Any Water Reducing Admixture capable of producing a large degree of water reduction or greatly enhanced flowability without causing undue set retardation or entrainment of air in concrete or mortar.  (Also see “Superplasticizer”)

Weathering    Changes in texture, color, chemical composition, strength or other properties due to effects of the environment or weather.  Independent of any changes due to direct mechanical wear.

Wet   Having visible free moisture; not dry.

Wetting Agent    Any substance that lowers the surface tension of liquids thereby facilitating the wetting of solid surfaces and permitting the penetration of liquids into the capillaries.