Accelerators: Admixtures that decrease the setting time by increasing the rate of hydration.

Admixture: A material other than water, aggregates, or cement that is used as an ingredient of concrete or mortar to control setting and early hardening, workability, or to provide additional cementing properties.

Aggregate: Inert solid bodies such as crushed rock, sand, gravel.

Binder: Hardened cement paste.

Bleed: To have water seep to the surface of the cement paste due to settling.

Calcination: Decomposition due to the loss of bound water and carbon dioxide.

Cement: Finely powdered mixtures of inorganic compounds which when combined with water hardens with hydration.

Cement paste: Cement plus water. When the mass has reacted with water and developed strength it is called hardened cement paste.

Clay: Type of soil consisting of very fine particles.

Clinker: The material that emerges from the cement kiln after burning. It is in the form of dark, porous nodules which are ground with a small amount of gypsum to give cement.

Compression: Forces acting inwardly on a body.

Concrete: A hard compact building material formed when a mixture of cement, sand, gravel, and water undergoes hydration.

Cure: To keep concrete moist during initial hardening.

Deformation: The process of changing the dimensions of a structure by applying a force.

Dormancy period: Time period that concrete retains it workability.

Elasticity: The ability of a material to return to its original shape after being stretched.

Forms: Holders in which concrete is placed to harden.

Gypsum: Calcium sulfate dihydrate, CaSO4.2H2O added to cement to regulate setting.

Hydration: The reaction of cement with water to form a chemical compound.

Kiln: High temperature oven.

Limestone: Mineral rock of calcium carbonate.

Mortar: Cement paste mixed with sand.

Pozzolan cement: Volcanic rock powdered and used in making hydraulic cement.

Porosity: The amount of empty space in concrete.

Portland cement: A cement consisting predominantly of calcium silicates which reacts with water to form a hard mass.

Retardants: Admixtures that increase the setting time by slowing down hydration.

Set: Transformation of cement paste or concrete from a fluid-like consistency to a stiff mass.

Slump test: Test used to determine workability.

Tension: The stress resulting from elongation.

Workability: How easily fresh concrete can be placed and consolidated in forms.

Concrete Table of Contents
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