Concrete Magazine demonstrates effective precast and in-situ concrete combination
A major redevelopment of the Broadmoor Hospital site (BHR) for the West London Mental Health NHS Trust enabled Kier Major Projects and specialist contractors PCE Ltd to provide, in partnership, economic build solutions for the ward buildings and entrance building that would meet the client’s high specification and security performance requirements.
Interior image (above) courtesy of West London Mental Health NHS Trust.
The final design solution for the four buildings meant that PCE was responsible for the design, detail, manufacture and erection of over 6150 precast concrete units. These were allocated into ten distinct product categories: twin wall; solid walls; architectural sandwich panels; prestressed hollowcore flooring; reinforced solid floor units; square and circular columns; beams; stairs; and landings.
A significant amount of in-situ concrete and associated reinforcement was also used within the design, predominately in the twin wall and flooring, which was cast on-site.
Off-site manufacture to exacting specification needs and tight tolerances with high-quality finishes was maximised to ensure rapid construction.
The correct choice of precast concrete component manufacturers was critical to the design for manufacture and assembly (DfMA) process, ensuring that the requisite production skills were available to produce concrete units to the required quality requirements and programme.
Eight different factories
The precast concrete components were manufactured at eight different factories, each selected for their expertise and specialism in specific products. Stringent quality control standards and co-operation with suppliers, including the carrying out of regular inspections at the manufacturing facilities, helped ensure that all of the concrete components arrived on-site fully finished and ready for immediate incorporation into the project.
During the manufacturing process over 10,000 mechanical and electrical components with positional accuracy were cast into the precast units, thus dramatically reducing the following trades’ fit-out period. Where applicable, composite in-situ reinforced concrete beams with a permanent steel shutter supporting the precast concrete floor units were incorporated into the design, to minimise the overall floor construction depth and provide an unobstructed floor soffit.
This maximised the flexibility for installation of pipe, cable and air-conditioning ducting runs for the large amounts of M&E services that were required for this project.
Extract and download courtesy of Concrete Magazine.
The DMC approach
- Designing a hybrid kit of parts to be…
- Manufactured from a variety of products to be…
- Constructed with a mindset of a manufacturing plant on site.