| 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, 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 Content | (Concrete Engineering) A quantity of cement contained in a unit volume of concrete or mortar, ordinarily expressed as pounds, barrels, or bags per cubic yard. |
| 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. |
| Chair(s) | (Concrete Engineering) In concrete formwork, the support for the reinforcing steel. |
| 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 |
| Condensation | (Concrete Engineering) When a moisture laden gas comes in contact with a cooler surface a change of state from gaseous to liquid occurs. |
| Consistency | (Concrete Engineering) The degree of plasticity of fresh concrete or mortar The normal measure of consistency is slump for concrete and flow for mortar. |