When used in conjunction with steel frames, precast floors and stairs make a commercially and structurally efficient building. Precast floors can also reduce the steel beam requirements in comparison to metal decking options.
Common problems
- Bearings reduced to minimum due to flanges and shear studs
- Connection details impacting on planks locations requiring cutting to suit on site
- Bolt heads and locations not taken into account in design.
Solutions
- Design collaboration Solutions
As a composite floor, shear studs can be factory welded rather than through metal deck welding to save program time.
However, special attention needs to be paid at design stage and coordination between the steel fabricators and precast manufacturers to ensure clashes between these elements are avoided. Poor collaboration will incur costly delays on site. In some cases of poor design, planks are unable to be installed and remedial work is required to allow installation. With plant and labour left standing waiting to continue the installation.
Initially the main contractor should appoint both contractors at the earliest possible stage of the project and the principal designer should coordinate discussions including the structural engineer. Flange width needs to be determined and shear stud positions clearly communicated to avoid reduced bearings for the precast planks.
The issue can also occur with connection details within the steel frames. Bolted details and column to beam connections must be communicated to the precast designer so they can design the necessary cut outs for manufacturing and avoid any unnecessary on site cutting.
PSS can site weld your shear studs post installation of the floor units. Subject to specification and information from the engineer, PSS will design the planks to receive the studs, welding gun and associated reinforcement. PSS can install all disproportional collapse requirements with additional tie bars, shear studs and the concrete topping.