Precast concrete frames involve an entire structure being fabricated off-site.
FP McCann manufactures three main types of precast frame construction:
- Portal Frames
- Column and Beam
- Crosswall Construction
Precast Portal Frames
Precast portal frames can be defined as two-dimensional rigid frames that have a rigid joint between the precast column and beam. The precast beamforming the roof at the top can be pitched or sloped. The main objective of this form of design is to reduce the bending moment in the beam, which allows the frame to act as one structural unit. Portal frame construction is suitable to use for wide span, single-storey buildings such as sheds or low-rise buildings with multiple floors such as warehouses.
FP McCann’s precast columns are available in a variety of sizes and shapes, including circular, square, rectangular or oval to suit all specifications. They may be single or double-storey height. Connections may be made via a base plate to the column or by reinforcing bars projecting from the precast unit, or set into a preformed hole in a foundation block and grouted into position. Foundation connections available include cast in base plates, dowel tubes or projecting bars.
- FP McCann manufactures a range of precast concrete beams including
- Ground beams – span between foundations or bases to support brick/ blockwork
- Spandrel beams- span between columns around the perimeter of a building, providing load-bearing support to floor and roof loads
- Spine beams – span the length of a building, providing load-bearing support to floor slabs on either side
- Lintel beams – span above door and window openings, providing load-bearing support to the structure above
- Balcony beams – are beams cast with an integral balcony
- Raker beams – span between columns, providing structural support for terracing units and can be made to any size or length
Precast concrete frames are cast in the same way as precast concrete cladding, but as they are designed as structural elements, have heavier reinforcement than is required for non-structural cladding.