| Bleeding, Bleed Water | (Concrete Engineering) A form of segregation in which some of the water in a mix tends to rise to the surface of freshly placed concrete. Known also as water gain. |
| Calcine | (Concrete Engineering) To alter composition or physical state by heating to a specific temperature for a specific length of time. |
| Calcium Aluminate Cement | (Concrete Engineering) The product obtained by pulverizing clinker consisting essentially of hydraulic calcium aluminates resulting from fusing or sintering a suitable proportioned mixture of aluminous and calcareous materials. |
| Capillarity | (Concrete Engineering) A wick-like action whereby a liquid will migrate vertically through material, in a upward direction; as oil in a lamp travels upward through the wick, |
| Carbonation | (Concrete Engineering) 1) Reaction between the products of portland cement (soluble calcium hydroxides), water and carbon dioxide to produce insoluble calcium carbonate (efflorescence). 2) Soft white, chalky surface dusting of freshly placed, unhardened concrete caused by carbon dioxide from unvented heaters or gasoline powered equipment in an enclosed space. 3) Carbonated, dense, impermeable to absorption, top layer of the surface of concrete caused by surface reaction to carbon dioxide. This carbonated layer becomes denser and deeper over a period of time. 4) Reaction with carbon dioxide which produces a slight shrinkage in concrete. Improves chemical stability. Concrete masonry units during manufacturing may be deliberately exposed to carbon dioxide after reaching 80% strength to induce carbonation shrinkage to make the units more dimensionally stable. Future drying shrinkage is reduced by as much as 30%. |
| Cellular Concrete | (Concrete Engineering) A lightweight product consisting of portland cement, cement-pozzolan, cement sand, lime-pozzolan, or lime-sand pastes, or pastes containing blends of these ingredients and having a homogenous void or cell structure, attained with gas forming chemicals or foaming agents. For cellular concretes, containing binder ingredients other than or in addition to portland cement, autoclave curing is usually employed. |
| Cement Gel | (Concrete Engineering) The colloidal gel (glue like) material that makes up the major portion of the porous mass of which hydrated cement paste is composed. |
| Change of State | (Concrete Engineering) The process whereby liquid is heated to the point of evaporation changing the liquid into a gas the condensation of a gas on a cooler surface returning it from gaseous to liquid form. |
| Cold Joint | (Concrete Engineering) A visible lineation which forms when the placement of concrete is delayed. The concrete in place hardens prior to the next placement of concrete against it. |
| Colloidal | (Concrete Engineering) A gel-like mass which does not allow the transfer of ions |