High-Early-Strength Concrete (also known as fast-track concrete), achieves its specified strength at an earlier age compared to normal concrete. This earlier age is the time period in which a specified strength should be achieved and may range between a few hours (or even minutes) to several days. Although it can be achieved using traditional concrete ingredients and concreting practices, the production of HESC will sometimes require special materials or techniques. Depending on the age at which the specified strength must be achieved and on job conditions, one or a combination of the following can be used in the production of HESC: type III or He high-early strength cement, high cement content, low water-cementing materials ratio, higher curing temperature, higher freshly mixed concrete temperature, silica fume, chemical admixtures, special rapid hardening cements, insulation to retain heat of hydration, and/or steam and autoclave curing.
High-early-strength concrete is used for prestressed concrete to allow for early stressing; precast concrete for rapid production of elements; high-speed cast-in-place construction; rapid form reuse; cold-weather construction; rapid repair of pavements to reduce traffic downtime; fast-track paving; and several other uses. In fast-track paving, use of HESC allows traffic to open within a few hours after concrete is placed. ...Show more