Formstress has a large range of precast concrete products.

Solutions that speed up construction times have always been in demand and the Formstress shell beam helps in this area by reducing the amount of on-site formwork and minimising the amount of beam reinforcing required.

Product Specifications

Precast shell beams are either 400 or 600mm wide with wall heights up to 600mm tall.

All Formstress shell beams are cast from 45 MPa (at 28 days) concrete.

When specifying precast shell beams, your project structural engineer should provide the number of strands, diameter required and the stress or alternately the ultimate midspan moment capacity required for the beam length.

Engineers should note that the shell beam contains a small cage of reinforcing. This steel is for construction and handling purposes only and should not be considered in the main beam design, including shear calculations.

Refer to NZS 3109:1997 Table 5.1 for precast construction tolerances.

Installation & Construction

All Precast shell beams need to be fully supported (shore loaded) during the construction process. Builders should install the props to the required levels prior to placing the beams. This should be achieved to within ±3mm. The propping system (designed by others) must be adequate to carry all construction loads.

Drilling holes through or cutting precast shell beams should only be undertaken with the written approval of a Formstress engineer.

General Notes

Contact Formstress Precast about any specialist needs you may have.

Before manufacture can commence the contractor shall sign off the precast shop drawings certifying that the shop drawings are dimensionally and structurally correct.

All Formstress precast units are provided with lifting eyes. Chains and strops must be of the correct length and not more than 30 degrees of vertical.

For temporary storage of precast shell beams provide bearers each end on level ground. Formstress do not recommend the stacking of shell beams.