A concrete frame is a load-bearing structural skeleton made up of reinforced concrete columns and beams, connected at rigid joints to transfer all vertical and horizontal loads down to the foundations. Because the frame itself carries the weight of the floors and roof, the walls between the columns are non-structural and can be built from lightweight materials or even replaced with full-height glazing.
The columns are vertical elements that carry compressive loads, while the beams span horizontally between columns to support the floor slabs above. Together they form a grid-like framework. The joints where beams meet columns are designed to be rigid, meaning they can resist bending forces and provide stability against wind and other lateral loads.
Application
Concrete frame construction is the dominant structural system for multi-storey buildings worldwide, from apartment blocks and office towers to shopping centres and hospitals. Its key advantage is flexibility: because the internal walls do not carry loads, the floor plan can be arranged and rearranged freely. Rooms can be made larger or smaller, and openings can be placed wherever needed.
The frame can be built in two ways. In-situ (cast-in-place) frames are formed by erecting formwork on site, placing reinforcement, and pouring concrete floor by floor. Precast frames use factory-made columns and beams that are transported to site and assembled with bolted or grouted connections. In-situ construction offers maximum design freedom, while precast construction is faster and produces cleaner finishes.
For DIY builders, a full concrete frame is rarely practical for small projects, but understanding the principle is useful. A simple post-and-beam arrangement using concrete-filled steel columns and a concrete ring beam can provide a frame-like structure for garages, carports, or open-plan extensions where large spans without intermediate walls are desired.
Concrete frames are designed by structural engineers who calculate the required sizes and reinforcement for each column and beam based on the loads they must carry.
Related terms
- Frame construction
- Column
- Beam
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