Additive materials introduced to accelerate the setting and hardening time of the concrete. Common components include aluminum sulfate, calcium chloride or other acidic substances.
Any material (apart from aggregate, water or cement) added in small quantities to produce certain modifications. The modifications could be made to either physical or chemical properties in both mold and hardened states. The properties usually affected are air entrapment, plasticity, and curing time. Common names include accelerator, plasticizer, superplasticizers, dispersants etc.
It is a mixture that forms the three-fourth volume of the concrete and is responsible for properties like structural performance, formation, and flow of cement paste. Usually contains rocks, sand, crushed stone, and other materials.
It is a vehicle used to take ready-to-use concrete from source to construction site. It contains a large drum that rotates continuously and prevents the concrete from solidifying before it is used.
Used to fill the gaps in concrete blocks. The composition is the same as of usual concrete used for cavity fill. However, the aggregate size is the smaller 7mm and the slump is of 120mm, ensuring that the mixture flows between the blocks.
The mixture used to fill the gap between the two layers of bricks. Generally used on a retaining wall or a wall supporting another structure on it. The composition is the same as Block fill; however, the aggregate size and slump differ.
It is a finely grounded powder that is one of the components in concrete. It acts as the adhesive in concrete and solidifies coming in contact with water.
Concrete is a building material used for construction purposes. It is a mixture of 4 components: mineral, binding agent, chemical additives, and water. Sand, gravel or crushed stone is usually the mineral used. The binding agent can be either natural or synthetic cement. Concrete is used in a variety of projects like roads, bridges, factories, waterways, and airports. In the case of domestic purposes like garage, floors, sidewalks, and patios, a mixture of sand, cement, and gravel is used to make concrete. The concrete is also usually reinforced with steel rods or wire mesh for better strength.
Various parameters like smoothness, texture, and hardness are used to describe the finished product. In case of floors, the surface is pressed with steel blades to form a dense protective coating. Paving are trowelled with a spin so that the surface attains a non-slip finish.
Simply called the Slab; used during the construction of a new building or house. It has deeper edge beams, apart from beams that run throughout the slab and is embedded into the ground.
It is the process of transporting concrete from source to destination. The source can either be the mixing location or the central plant, while the destination is the construction site. Agitator trucks are used to transport mixed concrete while preventing them from solidifying. Once on site, the concrete is transported to the precise location via wheelbarrows, conveyors or concrete pumps.
Curing refers to a variety of processes like evaporation of water/solvent, polymerization, hydration or some other chemical reactions. The objective of curing is to ensure that the concrete sets to the desired strength. The duration of setting depends upon many factors like cement type, desired strength, weather, dimensions of concrete section, mix proportion and expected exposure. Lean concrete mixes, used in dams etc., can take up to 3 weeks to set while richer concrete mixes may only need a few days. Curing is usually done within a temperature range of 20-30 degree Celsius.
Exposed Aggregate Finish
A method of finishing concrete used in projects with exposed exterior surfaces like patios and driveways. It is done by washing off the cement and sand from the top layer of the aggregate.
It is a material containing aluminosilicate and traces of lime. It is produced as a byproduct of burning coal in power plants. When combined with lime during the hydrothermal process, it can produce cement. It is a part of the concrete admixture.
A trench dug into the ground, which is filled with concrete once the rebar is inserted into the trench. Generally, a foundation has 600mm depth and 350mm width. However, it varies according to the soil type, so it is always wise to consult an expert before going ahead with the digging.
Mpa, or megapascal, is the metric unit to measure stress or pressure. In the case of concrete, the term expresses compressive strength. The strength varies with the purpose of concrete. It is usually 20mpa for footpaths, 25mpa for driveways and 32mpa for suspended slabs.
Sometimes, concrete carry notations like ‘N20/14’. Here, ‘N’ signifies Normal class concrete, 20 is the 20mpa strength while 14 refers to the 14mm aggregate size.
A term commonly used to refer to the mixture of all ingredients of concrete.
A common term used to refer the cement or the mortar.
Paving might refer to any large surface upon which concrete is to be placed, like footpath or driveways. It can also refer to the laying of pavers over the top.
A chemical agent used to increase the slump without water. It keeps the cement-water ratio unchanged while increasing the fluidity of the cement so that it is more workable and easier to place.
A process where the tendons are tensioned once the concrete has solidified and hardened. It can also be understood as pre-stressing reinforced concrete.
A pump mix is different from a regular mix so that it is easier to be pumped. This is usually achieved by using a smaller aggregate size compared to regular mix.
It is the concrete which is already mixed or batched at the central plant and delivered as such to the construction site, ready for placement. A common variation is a transit-mixed concrete, where concrete is mixed during transit via agitator trucks.
It is a common term for reinforcing bar. Rebars are inserted into the concrete so that it imparts a greater strength to the block and, by extension, to the entire structure. The steel bars are ribbed and come in various thickness/strength grades.
Screed refers both to the process of leveling off a concrete surface to attain a certain height, and the device used to do the same. Screeds are commonly available at stores, but they come in various sizes for various purposes.
It is the opposite of the accelerators. These are chemical agents that are used to delay or temporarily stop the setting of concrete.
Also known as concrete spraying, shotcrete refers to the pressurized projection of concrete or mortar at high speed onto a surface. Commonly used in pools or on battered walls.
It is the amount of wetness in a concrete. Slump is usually obtained by water, though there are other, more efficient agents. Concrete with low slump (say, 40mm) is dryer, stiffer and harder to work with compared to concrete with higher slump (say 120mm). Usually, a slump of 80mm is preferred.
Since the objective of the slump is to flow between voids, the slump test aims to check the plasticity of the concrete. A conical container, 30cm high, is used and the sample concrete is poured in it. When the cone is lifted, the concrete would fall from the bottom and form a slump. The amount of fallen concrete is called the Slump of the concrete. Water is generally used to increase slump, but higher slump also compromises with the strength of the concrete.
A straight, rigid piece of wood used to level or strike off the surface of the concrete, to either ensure a certain grade or to check the flatness of the finished grade.
A type of concrete admixture used to make wet concrete more fluid but without adding any water. Performs a similar function to plasticizers, but has a different composition.
It is essentially a concrete mixer that is used to mix the concrete when it is in transit.
Agitation via the energy of the freshly mixed concrete, aimed at even distribution and consolidation of the form. It is usually done through pneumatic or electric devices during the placement.