Precast concrete has been put to good use for a variety of detention and correctional facilities and the support buildings that serve a vital role in institutional complexes. Precast concrete wall panels, framing and floor/roof slabs are excellent building components that are both durable and secure.
Exterior walls can be sandwich panels with a layer of rigid insulation between whythes of reinforced or prestressed concrete. Special security hardware is often specified. Security door and window frames can be pre-installed in the precast concrete elements at a CPCI member precast plant to save time and money. On very large-scale projects, custom forms can be designed to produce special units such as entire single and double cell units. Otherwise, standard precast components can be successfully modified for prison construction.
As in most precast structures, using practical and economical joint details is most important. All joint treatments should recognize realistic production and erection tolerances. Exterior joints should allow movements and be weatherproofed to prevent air and water infiltration. When joints are exposed in high security locations, they are generally sealed with high strength, non-shrink grout. This material can be used to seal narrow joints and fill the cavities over recessed structural connections.
Calgary Remand Centre
The 17,193 m2, 350 cell Calgary Remand centre is constructed with exterior load bearing precast concrete sandwich panels forming the building envelope for the secure perimeter of the building.
"Special consideration was given to the vertical and horizontal joints between sandwich panels and the floor slabs." explains, David R. Coupland, MRAIC, architect. "Since the inside whythe of the precast sandwich panel provided an excellent air/vapour barrier, it was necessary to ensure a total air/vapour seal at all joint locations. The outside face and the rigid insulation was terminated 200 mm from the edges of the inside whythe of the precast sandwich panels on all sides. This allowed on-site installation of a thermofusible membrane that covered the panel joints. The vertical joints were then covered by vertical precast 600 mm wide panels to match the finish on the adjacent precast panels. Accent coloured metal panels were used to cover horizontal panel joints.
Security window galvanized pressed steel frames were cast into the precast concrete walls. The glazing was held in place with an aluminum pressure plate incorporating the proven "rain screen" principals of a curtain wall system. This provided a superior window to satisfy the "freedom wall" requirements of the secure perimeter, as well as a completely sealed, infiltration free window installation.
The system used to create a totally sealed building envelope also became the architectural expression unifying all elements of the exterior facade.
Owner/Propriétaire: Alberta Public Works, Supply & Services
Architect/Architect: CJM Architects Inc.
Engineers/Ingénieur: Read Jones Christofferson Ltd.
Contractor/Entrepreneur: Omsac Developments