Concrete filling

• Standard C40 pumpable concrete mix is used
• Fill rate is 2-3m height per hour
• Timing is flexible within construction programme

Large openings can be sealed off prior to site installation or as part of the site erection. Bi-Steel construction methods ensure that panel to panel and panel to interface connections do not leak.

At foundation level, the Bi-Steel is placed onto the concrete.  Gaps between the Bi-Steel panel and concrete slab are blocked by making an initial small height pour at the base.  Alternatively any gaps can be filled with grout.

Concrete filling of the Bi-Steel can proceed at a rate of 2-3m height per hour.  For large cross sectional areas of core, this rate may be limited by the site supply of the concrete. Given suitable concrete, there is no limit on the height of a pour so long as the rate of fill is controlled.

A recommended method of construction is to erect the Bi-Steel structure to module height , erect the surrounding steelwork and then concrete-fill the core to this level.  Corefast building cores can be constructed to full height, with either the concrete or surrounding steelwork being the immediate follow on activity.   The method used is the choice of the contractor and is not generally critical to the design of Corefast.

The grade of concrete is designed to be a standard C40 concrete mix. No special additives are required for the basic design case, however a high slump (100-150mm) is desirable.  Where ultra-fast construction times are required, specially designed mixes can be used to give early strength so that pressures within the panels are controlled. For ultimate ease of filling a self-compacting concrete can be used.