Abrams' Law-The rule of concrete stating that with given materials, curing, and testing conditions, concrete strength is inversely related to the ratio of water to cement. Low water-to-cement ratios produce higher concrete strengths Accelerator - Chemical substance added to a concrete mix that reduces the set time by increasing the rate of hydration.
Acrylic Sealer- An acrylic solvent or water-based sealer that forms a protective film on the surface of the concrete that imparts a sheen that highlights the beauty of regular and decorative concrete
Aggregate – Concrete is a mixture of water, Portland cement, and aggregates (sand and / or stone). Sand is considered a fine aggregate, while any stones are coarse aggregates. Apron - A slab of concrete, often at an entrance for vehicles, that extends beyond a building's entrance. Broom finish - Surface texture obtained by pushing a broom over freshly placed concrete. Bull Float – a tool comprising a large, flat, rectangular piece of wood, aluminum, or magnesium usually 8 inches wide and 48 inches long and a handle 4 to 16 feet in length used to smooth unformed surfaces or 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 Concrete - Concrete is not the same as cement. Concrete is a combination of cement as a binding agent, chemical additives, water and mineral. This combination, when properly mixed and placed, hardens into an excellent building material for a wide variety of uses. Control (or contraction) joint - Sawed or tooled groove in a concrete slab used to regulate the location of cracking Construction Joint - are surfaces where two successive placements of concrete meet. They are typically placed at the end of a day's work, but may be required when concrete placement is stopped for longer than the initial setting time of concrete. In slabs they may be designed to permit movement and/or transfer load.
Cubic Yard – Unit of measure for ready mix concrete. Concrete is ordered, sold, and batched by volume. Curing – The maintenance of the proper moisture and temperature of concrete is its early stages that desired properties may develop. Finishing - Leveling, smoothing compacting, and otherwise treating the surface of newly placed concrete or concrete overlays to produce the desired appearance and service properties
Float finish - Surface texture (usually rough) obtained by finishing with a bull float or hand float. Flatwork - Mostly flat-surfaced concrete work, including sidewalks, driveways, basements and concrete floors. Grade - A building site's (or buildings) existing or proposed ground level or elevation. Also used in categorizing building or construction levels, e.g. above grade, on grade, or below grade.
Hand float - A smaller handheld version of the bull float, ranging in length from 12 to 18 inches. Especially useful for floating along the perimeter of forms or to work in tight spots. Hard-troweled finish - Surface finish obtained by using a trowel with a steel blade for final finishing of concrete. Often used where a smooth, hard, flat surface is desired. Hover Trowel - A patented lightweight power trowel developed specifically for precision finishing of epoxy, polymer modified, and cementitious overlay systems. Kneeboards - Boards used by concrete finishers to kneel on when hand floating or troweling concrete flatwork. Margin trowel - A steel trowel with a small, rectangular flat blade about 5 to 8inches in length and a short handle. It has multiple uses, including scraping off concrete from finishing tools and applying patching materials. Mix design - Specific proportions of ingredients (cement, aggregates, water, and admixtures) used to produce concrete suited for a particular set of job conditions. 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. Portland cement – A hydraulic cement that sets and hardens by chemical interaction with water. Ready-mixed concrete - Concrete that is batched or mixed at a central plant before delivery to the job site for placement. Rebar (or reinforcing bars) - Ribbed steel bars installed in cast-in-place concrete to provide flexural strength. Rebar come in various diameters and strength grades Reinforced concrete - Concrete construction that has steel rebar or welded wire mesh embedded in it to provide greater tolerance to tension and flexural stress Sack - A quantity of and Cement. One sack weighs 94 pounds Sack mix – The amount of sacks of cement in a cubic yard of concrete. Specified when ordering, concrete is typically referred to as a 5 sac mix. The sacks of cement needed in a mix are usually specified in either the plans or the specifications of a project. More sacks = more strength. Salt finish - A textured, decorative finish obtained by broadcasting rock salt onto fresh concrete and then using a roller or float to press the salt particles into the surface. After the concrete sets, the salt is washed away to reveal a speckled pattern of shallow indentations Saw-cutting - Using a concrete saw with abrasive blades or disks to cut joints or score patterns into hardened concrete
Screeding – The operation of forming a surface by the use of a screed or strike-off and screed guides. (typically, the forms) Set - The coition reached by concrete when plasticity is lost, usually measured in terms of resistance to penetration or deformation. Initial set refers to concrete that has reached first stiffening. Final set occurs when concrete attains full rigidity
Set time – A measurement in hours and minutes of the hardening of concrete to resist a measure of penetration. 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. Stamped overlay - Similar to conventional stamped concrete, but can be applied to existing concrete. A cementitious topping is applied at a thickness of 1/4 to 3/4 inch and then stamped to mimic brick, slate, and natural stone. Color options include dry-shake color hardeners, colored liquid or powdered release agents, acid stains, dyes, and tinted sealers Stamping mats - Rigid or semi-flexible polyurethane tools for imprinting stone, slate, brick, and other patterns in stamped concrete surfaces. Stamping mats usually imprint a shallower pattern than platform tools. Strike off - To level off freshly placed concrete to the correct elevation. Slump – A measure of consistency of freshly mixed concrete, measured in inches. It is the distance that freshly mixed concrete subsides when a conical mold (slump cone) is lifted from the test specimen. Increasing the slump is typically done by increasing the batch water. This method also will begin to erode the strength of the concrete is the slump is raised higher that its designed level. Sub grade – The prepared and compacted soil made to support a structure or pavement system. Tamper (or pounder) - A handheld impact tool used to firmly press stamping mats or texturing skins into fresh concrete to ensure a complete imprint. Trowel - A flat, broad-bladed steel hand tool used to compact the paste layer at the surface and provide a smooth, flat finish. Also useful for applying topping or repair materials. Available in different shapes (with rounded or square edges) and lengths(ranging from 8 to 24 inches). Smaller trowels are useful for borders, work in restricted areas, or to work in flashing accents of dry-shake color hardener. Trowel finish - The smooth or lightly textured surface finish obtained by troweling. Water-cement ratio - The ratio of the amount of water to the amount of cement in a concrete mixture. The key to producing high-quality concrete is to keep the water-cement ratio as low as possible without sacrificing workability. Water reducer - An admixture that either increases the slump of freshly mixed concrete without increasing water content or maintains workability with a reduced amount of water without affecting the strength. Welded wire mesh - A woven mesh of wire strands, welded at each intersection, used to reinforce concrete slabs. Also called welded wire fabric Workability - The ease with which concrete or other cementitious materials can be mixed placed and finished Working time - The amount of time available for placing and finishing a cement-based material before it begins to set. Often depends on the ambient temperature and substrate temperature Volumetric mixer – A concrete mixer that measures and produces plastic ready mix concrete by volume rather than weight. Volumetric mixers meter their concrete output as they produce the concrete, also known as continuous batching.