| 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%. |
| Cement, Portland (ASTM C150) (Concrete Engineering) | A powdery substance made by burning, at a high temperature, a mixture of clay and limestone producing lumps called “clinkers” which are ground into a fine powder consisting of hydraulic calcium silicates. For non-portland cements, see aluminous cement. |
| 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. |
| Cementitious | (Concrete Engineering) Having cement-like, cementing, or bonding type properties. Material or substance producing bonding properties or cement-like materials. |
| Chair(s) | (Concrete Engineering) In concrete formwork, the support for the reinforcing steel. |
| Colloidal | (Concrete Engineering) A gel-like mass which does not allow the transfer of ions |
| Dry Rodded Weight | (Concrete Engineering) The weight of dry aggregate rodded into a cylindrical container of diameter approximately equal to the height, each of 3 layers rodded 25 times, and the excess aggregate struck off level with the top of the container |
| Entrained Air (See air entrainment) | (Concrete Engineering) Microscopic air bubbles intentionally incorporated in mortar or concrete, to improve workability and durability (usually imparting a higher degree of resistance to freezing and thawing). |
| GFRC - Glass Fiber Reinforced Concrete | (Concrete Engineering) Concrete panels, usually architectural designs, reinforced with a high zirconia (16% minimum), alkali-resistant glass fiber. Optimum glass fiber content of 5% by weight. Lower fiber content results in lower early ultimate strengths, higher fiber content can produce composite compaction and consolidation difficulties. |