Division 3 Concrete
Concrete (Cast in Place)
- Building interior structural concrete painted surfaces should not be scheduled to receive a rubbed finish. If a smooth plaster-like finish is desired, specify a thin coat of veneer plaster over the concrete substrate.
- Building exterior expressed concrete structural frame should be detailed (incorporating insulation and finish systems) to prevent thermal loss or gain.
- Exposed interior concrete floors should be sealed. A hardener is required where the floor surface is subject to heavy, impact, and/or rolling loads.
- A sample panel of exterior exposed “Architectural” concrete should be provided to establish an acceptable standard of workmanship/quality concerning finishing, texture of formed material, etc. The concrete used in the sample panel should be furnished by the project concrete supplier, and should represent the approved mix for strength and texture.
- Exterior concrete flatwork should be six inches nominal thickness, 3000 PSI air-entrained concrete, reinforced with welded wire fabric located two inches below the top surface. The flatwork should be placed over a four inch aggregate stone base, and where intermittent vehicular traffic is anticipated, be a minimum of nine feet wide with a six inch aggregate stone base. The top surface should be broom finished with tooled joints at a maximum of six feet on-center. Avoid saw cut concrete paving except in service areas.
- Avoid the use of concrete finish for wide monumental stair applications unless experienced care is taken in detailing the steps and the construction is executed properly. Use stone, brick, or precast concrete steps if possible.