Precast Concrete Solutions
Precast concrete solutions
Precast concrete off-site wall construction is a fast and practical way to produce multi-unit structures across all building sectors, in a fraction of the time associated with traditionally built projects. The visual possibilities and technical benefits appeal respectively to clients, architects and contractors.
Taylor Maxwell offer a range of architectural and structural precast components. This portfolio includes full structures, sandwich panels and facade panels, which are available in a variety of material finishes including acid etched, grit blasted, polished, exposed aggregate, stone faced, brick faced and tile faced.
A facing brick finish can be used for most bespoke precast-concrete applications, including arches, columns, wall panels, balconies, soffits and retaining walls. A combination of precast-concrete finishes can be used within the same or adjacent units, and smaller elements can be used in combination with traditional brickwork, such as brick-faced lintels or underslung soffits.
As a guide, facade panels are typically around 200mm thick, incorporating 50mm facing brick (half-brick) and 150mm concrete. As with all precast cladding, insulation, windows and other facade features can be factory-fitted if required.
Insulated precast sandwich panels provide a ready-made external building envelope. The panels are constructed off-site and comprise of an outer leaf of precast concrete, an insulating layer and a structural inner leaf of plain grade concrete with a powder floated internal finish. The external skin is connected to and supported by the internal skin using proprietary ties which have a low thermal conductivity and eliminate potential cold bridging.
If choosing a facing brick finish, the selection of brick type should be a key consideration, not only for visual impact but for manufacture and overall cost. Purpose-made precast brick slips or practically any cut traditional brick material can be used, but not all brick types are appropriate or as easy to bond into concrete.
Colour uniformity of the brick material must be considered, and pallets should be mixed to minimise any obvious variations on a facade. This is particularly important for large expanses of brickwork, or where adjacent panels are manufactured at different times, decreasing the risk of colour changes between panels. This needs to be stated in the material specification.
As with any visible precast component, the location of where any two panels meet is a key design decision and should be considered very early in the facade design. Joint widths are typically larger than the 10mm mortar joints but may be comparable with the movement joints required of contemporary brickwork. They are determined by the tolerances necessary for manufacture, anticipated natural shrinkage and thermal expansion and the tolerance needed for installation. Panels should be designed to prevent them exceeding 20mm.
Bricks are placed facing-side down in the concrete mould, arranged in the specified bonding pattern. Templates are commonly used to hold the bricks in position with spacing left for the mortar joints, non-standard bonding patterns or brick sizes will require bespoke spacing templates.
Once the bricks are in place, the joints may need additional fill to prevent the concrete from seeping through to the face of the brickwork, this is traditionally done with sand. At this point, reinforcement and any lifting eyes and fixing supports are put into position and the concrete is poured into the mould.
Brick slips offer the time-efficient option of pre-filling the mortar joints before the concrete is poured. The mortar is simply placed from behind, effectively cast in place rather than pointed. The profile of the mortar joint is created by the inverse profile of the brick spacers. Joint profiles available using this process create either a recessed or bucket-handle finish.
Once the concrete has cured, approximately 24hours later, the formwork is struck and the panels are turned over. The brickwork is then cleaned and, where required, mortar joints pointed before preparation for site delivery.
Brick-faced concrete panels can allow increased design freedom for brickwork and be a very effective means of combining the aesthetic of brick with the benefits of offsite manufacture. They are also a cost-effective way of achieving intricate brick detailing, which is otherwise challenging without the appropriate skills.
Where access is restricted, or the project programme demands fast on-site construction, precast architectural panels are the ideal solution. All units are manufactured off-site and are delivered ready for final preparation and decoration.
Lifting eyes are typically located to the rear of the panels, but one advantage of brick-faced concrete units is that they can be placed on the surface if required to help with installation. The missing bricks are then fixed over the lifting positions once the panel is in place.
Mortar joints can be pointed in the factory or on site depending on the project requirements. Pointing on site can take place once the panels have been installed, or on the ground before fitting which would remove the requirement for scaffolding.
Precast concrete can be provided in a variety of colours and finishes, utilising a large choice of aggregates and pigments.
Architectural concrete can be both structural load-bearing or non-structural, such as cladding. All architectural projects are designed and manufactured in an entirely bespoke manner.
Concrete is durable, strong and resistant to impact. It also has excellent fire-resistant and acoustic properties.
Design and manufacture off-site ensures consistent quality and lower construction costs.
Units can be manufactured to suit different building structures.
Fully finished /
Brick, stone or tile faced units can be supplied fully pointed.