An aggregate used to increase the abrasiveness of a concrete slab.
The total volume of concrete occupied. This is found by dividing the weight of each ingredient by its gravity, times by the weight of one cubic foot of water.
The absorption of water, usually shown as a percentage of the dry weight.
Until the aggregate is fully saturated, water losses can occur.
A material added to a concrete mix to either speed up or reduce the setting time. Examples include: calcium chloride, aluminium sulfate or other acidic materials.
Items such as shoring, scaffolding, frames and forms all used when placing concrete.
A mixture that is not an aggregate, cement or water, that is added to the mix in order to make certain modifications e.g. plasticity, curing time or air entrainment. The admixture is commonly referred to as accelerators, plasticizers or water-reducing agents.
A mixture of particles that makes up around 75% of concrete. This can include materials such as, crushed stone, rock and sand. This helps improve the structural performance of the concrete, including the flow and formation.
Tests performed on aggregates to determine the chemical and physical properties of it. For instance, absorption, abrasion and soundness tests are some of the most common ones carried out.
Concrete that extends from the entrance of a building, particularly used for vehicular traffic e.g. at an airport or hangars.
Either structural or non-structural concrete that will be permanently exposed so needs to therefore be uniform and aesthetically pleasing. This type of concrete is often cast in a mould and has a patterned surface.
A black petroleum residue that is often used as a roofing material, for lining walls of reservoirs, swimming pools and for resurfacing roads. It can be either in solid or liquid form, depending on the temperature, and should not be confused with tar - as it is a similar looking substance.
A mix of coarse materials, such as sand and stone, which is laid as a base underneath concrete.
A layer of a certain thickness that is formed on the sub-base of a pavement. This is laid in order to distribute loads, provide drainage and even minimise frost.
The quantity of concrete produced from one mixing operation i.e. one batch of concrete.
A base that has been specifically prepared for either masonry or concrete.
The cement paste and aggregate joining together.
An accessory whereby one end of the brace is attached to the form and the other is anchored to the ground. The brace offers temporary support for aligning vertical concrete formwork.
A small hand-held tool used to finish concrete curb and gutter work.
A common chemical, calcium chloride is an additive used as a catalyst to speed up the curing time of ready-mix concrete.
The pouring of a liquid material into a mould that can physically change its form as it solidifies.
A fixed form whereby permanent, pre-cast concrete forms are created.
A fine, grey powder that when mixed with water will harden and create concrete.
The ratio of cement mix to aggregate mix. This is measured in weight or volume.
Cement content / cement factor
An amount of concrete contained in a unit volume. This is usually expressed in pounds, bags per cubic yard or barrels.
A container with a rotary motion used to mix all the concrete ingredients together. This can either be electrically powered or manually operated.
Cement mixtures are a ratio of cement: sand: aggregates and different quantities can be mixed to achieve different consistencies:
1: 2: 3
Often used for roads and waterproof structures.
1: 2 ½: 4
Often used for reinforced work, such as floors, roofs, sewers and conduits.
1: 1 ½: 5
Often used for foundations, piers, walls etc.
1: 3: 6
Often used for mass concrete work, stone masonry or large foundations.
Different types of cement that can be mixed, including:
Suitable for many residential construction purposes but should not be exposed to extreme temperatures or high sulfate soils.
Type II: Moderate
Suitable for use in drainage structures where sulfate concentrations are higher than average.
Type III: High Early Strength
Suitable for when strong concrete is required quickly e.g. replacing old forms.
Type IV: Low Heat
Suitable for when the amount of heat generated during curing needs to be kept to an absolute minimum, and when strength is not needed straight away e.g. for dams.
Type V: Sulfate Resisting
Suitable only for where construction is exposed to severe sulfate action e.g soils with high alkali levels.
A material that is not cement but that shares the same properties of cement e.g. Portland cement and lime.
A building material that consists of a mineral (commonly sand or gravel) and a binding agent (cement), a chemical additive and water. It is a popular material used mainly in construction, road building, airports, factories and bridges.
A hollow masonry unit that is larger than the size of an average brick.
The plasticity of fresh concrete. This is usually measured by the consistency of the slump.
The hardening of concrete or other wet materials. This is the final process to laying concrete and happens when water evaporates. The weather conditions, mix proportion, size and shape of the concrete can all affect the length of time it takes to cure e.g. lean mixtures can take 3 weeks but rich mixtures only a few days.
A method used to repel water on concrete, stone or masonry. This prevents surfaces from absorbing liquid, such as rainwater.
Lubricant applied to a dowel, placed in slabs to allow movement in the joints.
Concrete with a low water content. It is a stiffer mixture, ideal for placing on sloping surfaces.
The reduction of moisture in concrete.
Edger (edging trowel)
An edging trowel tool used to finish the edges and corners off of fresh concrete.
A divider that allows the surface to expand and usually consists of a fibrous material. This is placed in between concrete slabs to allow movement.
Exposed aggregate finish
Washing away the cement and sand mixture from the top layer of aggregate. A technique used regularly on driveways and patios.
Concrete forms used to create curb profiles. They are attached to the curb and gutter by hooking to the division plate.
Fiber reinforced concrete
A type of concrete that has fibres added to the mix. The fibres can be made from stainless steel, carbon or glass.
Aggregate made up of very fine particles. The particles are so fine, they can pass through a ½ inch sieve and number four sieve.
This involves the compacting, smoothing and leveling of fresh concrete in order to create the desired look.
Metal forms made from spring steel, used for shapes such as islands, curbs and other similar forms.
The concrete foundation of a structure that supports the load and distributes the weight of the building evenly over the ground. The footings are always wider that the actual structure.
A structure or mold used for temporary support and containment of concrete while it gains sufficient strength to self-support.
The substructure, including the footings, below the ground floor of the building.
High quality moisture protection used for below-grade exterior concrete and wall damp-proofing. It has the consistency of black tar.
Glass Fiber Reinforced Concrete (GFRC)
A thin material often laminated to a plywood and used in wall systems. It works in a similar fashion to concrete but does not perform quite as well.
Refers to the existing level or surface of the grounds to a building. For instance, a road’s incline or decline presented as an average that is either above grade, below grade or on grade.
This encourages the curing process of concrete.
High-pressure steam curing
Also known as autoclave curing, this is a method of using steam to cure cement products in an autoclave with temperatures between 340°F and 420°F.
Method by which concrete is poured into foundation forms, leaving behind voids that create a honeycomb appearance.
A certain amount of stiffening of the cement mix. The amount is indicated in hours and minutes that is required for the cement to stiffen sufficiently.
This refers to the stresses that occur before any losses happen.
A concrete tamper tool designed to depress aggregates in concrete mixes. It helps to bring sand and cement grout to the surface of the slab.
Two or more building materials are joined together. The two materials can be held together either by cement, mortar or glue to name a few examples.
A tool to help judge the consistency of fresh concrete. This can be used as an alternative method to slump testing.
Similar to straight forms but with drilled holes along the centre with a bolted keyway (which can be detached when straight forms are needed). This is commonly used to pour keyed slabs with.
An oven, furnace or an enclosure of some kind to either harden, bake, char or burn various materials.
A single layer of concrete.
Nylon string used as a guide to set the concrete to grade.
Someone who builds stones, brick and concrete units.
A mixture of mortar, sand and water. This is classed as a Portland cement that helps make mortar more workable.
Any large volume of concrete with dimensions vast enough to require certain measures are taken in order to cope with the heat generation.
A piece of equipment used for blending two or more materials together that is used to manufacture concrete.
A combination of cement, sand and water, used for masonry work.
A slang term used in place of cement or mortar.
Hydraulic cement that is not hydrated.
Concrete mixture made up from coarse aggregates only.
Concrete that has not been subject to either air-entraining admixtures, nor air-entraining cement.
The outside area of a bend.
Heavy use of vibrations during placement to segregate fresh concrete.
Typically masonry materials that are laid down on the ground to make an even surface.
Concrete that has not been reinforced, or only reinforced for shrinkage.
A condition of concrete whereby it will sustain deformation time and time again, in any direction.
This property of concrete will determine how easy or hard it is to mould, in terms of how strong its resistance is.
Concrete that is cast into shapes using reusable forms. This can be transported easily as it is fully cured.
Concrete that is ready-mixed.
A special concrete (usually a small rock aggregate mix) that is used in a concrete pump.
Aggregates that contain substances that are reactive with products of Portland cement. This can result in harmful cracking, staining or expansion.
Concrete that is already mixed before being delivered to a construction site, so it is ready for placement straight away.
Concrete suitable for use at high temperatures.
Concrete that is reinforced with steel bars. This type of concrete is more able to withstand any tension.
A substance used to avoid concrete from bonding to a surface i.e forms.
Adding water to concrete that has stiffened - however this is not usually recommended as it can affect the strength of the concrete.
Breaking off the hardened surface of concrete.
Following the pouring stage, the concrete needs to be levelled off. This includes scraping off any excess concrete above the plane.
A decrease in volume via drying or chemical changes.
Concrete pavement that is used in driveways, basements and garages.
A hydraulic cement that is the product of the reduction of iron ore to iron.
This test is widely carried out to determine the plasticity of concrete. A sample of concrete is taken, if the concrete flattens in a pile 4” high, then it has an 8” slump. If more water is added to the concrete mix, then the strength of the concrete decreases but the slump increases.
Surface sections of the concrete either peel or chip away. This is due to the overuse of salt or an inferior concrete mix.
Removing the formwork from concrete.
A layer of aggregate material laid underneath a stone base.
Introducing water to the cement mix to produce the right consistency.
Concrete that has been mixed on the back of a truck during transportation.
The smoothing and compacting of fresh concrete, using a trowel.
A mixer able to mix concrete on the back of a lorry during transportation.
A vibrating machine that helps level out fresh concrete.
Either pneumatic or electric agitation of fresh concrete via high frequency impulses.
Proportion of water (only that absorbed by aggregates) to cement, in a concrete mixture. This is stated as a decimal by weight e.g. 1:2:4 is 1 cubic foot of cement, 2 cubic feet of sand and 4 cubic feet of gravel.
This material can help make freshly mixed concrete more workable, without adding more water to the mixture. Similarly, it can maintain the workability of the concrete by reducing the amount of water present in the mix.
A tool that is used to help extract moisture from concrete.
A substance that facilitates the wetting of solid surfaces and the penetration of liquids.
The measurement of concrete e.g. 1 cubic yard is 27 cubic feet or 3’ x 3’ x 3’.
The volume of freshly mixed concrete.
Zero slump concrete
Concrete mix that has very little water, so no slump is created.