| Air Entraining Agent | (Concrete Engineering) An addition for hydraulic cement, or an admixture for concrete or mortar which entrains air in the form of minute bubbles in the concrete or mortar during mixing. |
| Blast Furnace Slag | (Concrete Engineering) A non-metallic waste product developed in the manufacture of pig iron, consisting basically of a mixture of lime, silica and alumina, the same oxides that make up portland cement, but not in the same proportions or forms. It is used both in the manufacture of portland blast furnace slag cement and as an aggregate for lightweight concrete. |
| 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. |
| 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. |
| 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. |
| Dispersing Agent | (Concrete Engineering) An admixture capable of increasing the fluidity of pastes, mortars, or concretes by reduction of interparticle attraction. |
| HRM High Reactivity Metakaolin. | (Concrete Engineering) Refined form of an ASTM C618, Class N (natural) pozzolan. A high performance, mineral admixture, similar in performance to silica fume, additionally comparable in cost. Pure white powdered in form will, not effect the natural color or darken concrete as silica fume does. Suitable for high-performance color matching in architectural concrete. Dosage at 5% to 10%, of cement by weight. No bleed water, better finishability, more creamy, cleanup is easier with slightly higher 28 day strengths and 25% - 35% less plasticizer is required than silica fume. |
| Mixing Speed | (Concrete Engineering) Rate of mixer drum rotation or that of the paddles in a pan, open-top, or trough type mixer, when mixing a batch; expressed in revolutions per minute (rpm) or in peripheral] feet per minute of A point on the circumference at maximum diameter. |
| Neat Cement-Paste | (Concrete Engineering) A mixture of water and hydraulic cement, both before and after setting and hardening. |
| Non-agitating Unit | (Concrete Engineering) A truck-mounted unit for transporting ready-mixed concrete short distances, not equipped to provide agitation (slow mixing) during delivery. |