Terms & Definitions
Abrasion Resistance - the capacity of a material to resist degradation from friction against other materials.
Acid Stain - a type of concrete stain which contains colorants dissolved in an acid solution. The colorants are chemically bonded to the concrete during the reaction between the acid and the alkaline materials in the concrete surface.
Acrylic Resin - a polymer used in an emulsified form to make clear coatings. Can be modified with Methyl Methacrylate which is a form used to make hard plastics with excellent light transmitting qualities
Adhesion - a force which causes two substances to bond together
Admixture - An ingredient in concrete other than water, portland cement, and aggregate used 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 mixture of sand, rock, crushed stone, expanded materials, or particles, both enhances the structural performance of concrete and improves cement paste's formation and flow. Aggregate usually constitutes about 75% of concrete volume. In regards to concrete coatings, silica is often used as the aggregate.
Base Plate - The part of a standard framed wall which rests horizontally on the floor, and to which vertical studs are attached.
Binder - A binder is any material or substance that holds or draws other materials together to form a cohesive whole mechanically, chemically, or as an adhesive. CEMENT is the binder in concrete.
Broom Finish - Surface texture obtained by pushing a broom over freshly placed concrete.
Cement - Cement is not the same as concrete, but rather one component of concrete. Cement, a combination of finely ground materials, hardens when mixed with water to become the "glue" in concrete, also known as a BINDER
Chemical Bond - A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds.
Cold Joint - A linear transition in a concrete slab where two separate loads of concrete mix were poured adjacent to one another but after one was sufficiently plasticized to prevent the two from mixing and curing as one unit
Control Joint - Control joints (often confused with EXPANSION JOINTS) are cut or tooled into the concrete at regular intervals to allow cracking to occur in a controlled fashion.
Cream - A term used to describe the "fines" of concrete mix which are distributed at the surface of a pour, and contain no aggregate.
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.
Densification - A process in which a chemical is applied to concrete, causing a reaction which forms additional crystals filling microscopic pores in the surface of the slab. The surface becomes harder, smoother, and less permeable.
Density - The measure of how compact the microscopic structure of concrete is. As density increases, porosity and permeability decrease.
Dowel - A short steel rod inserted into a hole drilled into an existing concrete slab which ties a new pojr to the existing, preventing excessive movement between the two.
Dusting - A deterioration of a concrete surface which results in small dust particles being released.
Dye Stain - 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 hue
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.
Expansion Joint - Sawed or tooled groove in a concrete slab that is often filled with used to allow expansion or movement of adjoining structures due to the contraction of construction materials or movement and vibration from ground settlement and earthquakes.
Form - Either a temporary or permanent mold into which concrete or similar materials are poured. Usually made up of timber such as 2x4s and 2x6s, forms can also be made out of plywood, styrofoam, or reusable plastic framework.
Grade - The upper level of a floor or substrate.
Hardness - The measure of a concrete slabs resistance to damage from weight
Heat Cure - The chemical process by which a concrete mixture solidifies. Temperature is a primary factor is the speed of this reaction.
Hydration - The chemical reaction between cement and water that causes concrete or other cement-based materials to harden.
Level - No slope. If a slab is perfectly level, water will not move off of it. A slab can be "flat" but not "level."
Mechanical Bond - A bond between two materials which is created by shapes in the surfaces which "hook" them together in much the same way as links in a chain hold together, or velcro strips hold onto each other.
Moisture Cure - The process by which a coating achieves its full hardness by releasing or interacting with water vapor.
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.
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.
Penetrating Sealer - A sealer with the ability to penetrate into the concrete surface to increase water repellency. Penetrating sealers chemically react with the concrete preventing water and salt penetrating down through the concrete.
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.
Polyurea - A polymer coating with very high tensile strength and abrasion resistance
Porosity - The measure of the void (i.e. "empty") spaces in concrete.
PSI - "Pounds per Square Inch." A measure of concrete's resistance to fracture from compression or weight. Note: ordering a 3500 psi ready mix does not ensure that your slab will withstand that much weight because the finishing and curing processes have more effect on the final compressive strength than the mixture from the plant
Pump Truck - A concrete truck outfitted with a hose and a pump to allow concrete to be poured in areas where a standard truck and chute cannot reach or is not feasible.
Ready Mix - Concrete that is batched or mixed at a central plant before delivery to the job site for placement.
Rebar - Ribbed steel bars installed in cast-in-place concrete to provide flexural strength. Rebar come in various diameters and strength grades.
Reflectivity - A measure of gloss on a polished concrete surface (link to ASTM standard)
Remesh - A term used by concrete contractors for steel wire mesh used as light reinforcement for concrete slabs.
Resin - A highly viscous substance which can be converted into polymers. Absent of a reactive hardener, resins do not "dry out".
Scaling - is caused by water entering concrete and forcing the surface to peel, pop out, or flake off. Concrete spalling is most likely to occur on exterior surfaces that are exposed to freeze and thaw cycles. Causes include: high water cement ratio in the concrete mix, lack of air entrainment, improper finishing, and inadequate curing.
Shotblasting - An abrasive blasting method using round iron shot to clean and profile concrete surfaces.
Shrinkage Crack - When concrete is placed; typically that concrete contains more water than is required to hydrate the cementitious materials that the mixture contains. This excess water is for workability and placement purposes. Most of this excess water begins to exit the concrete during placement/curing and causes the concrete to shrink. While the concrete is shrinking, many things such as reinforcement or the subgrade restrain the concrete. This restraint creates tensile stresses in the concrete slab which in tum may produce shrinkage cracks. Shrinkage cracking can be the unfortunate end result of excess water added into the pour, improper finishing techniques or control joints not being cut into the slab or at the proper time and depth.
Silica - A compound which is responsible for the composition of quartz. Used as a fine aggregate in numerous products, coatings, and concrete
Skid Resistance - A measure of a surface resistance to slippage versus another surface. Used to predict a floor surface's slip properties for foot traffic. See ASTM standard.
Slump - A measure of consistency of freshly mixed concrete, as determined by the distance the concrete slumps after a molded specimen is removed from an inverted funnel-shaped cone.
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.
Stress Fracture - A break or crack in concrete caused by lateral movement.
Surface Profile - A measurement of the roughness of a concrete surface
Topical Sealer - A coating which builds a film on top of a concrete surface.
Urethane - A type of polymer used in concrete coatings and fillers which has excellent resistance to abrasion and chemical attack.