Temporary Propping
If temporary propping is required (refer to the temporary propping tables), props should be placed at the correct centres prior to laying the KF57® sheets. Generally, timber or steel bearers with a minimum dimension of 75mm x 75mm are used on vertical props. The props should be installed so as to prevent settlement during loading by wet concrete and other construction loads. Wide ply strips, of 300mm wide, may be positioned above the header bearers to assist in dispersing the load and minimise any local deformation of the decking due to the headers. Temporary props should only be removed after the slab has reached sufficient strength (at least 75% of the specified 28-day strength). The full design load may only be applied once the slab has achieved 28-day strength.
Edge-form
Galvanised steel edge-forms can be used for the retention of wet concrete to the correct level at the decked floor perimeters. KF57® edge-form is usually shot-fired to the steel support structure or to the KF57® deck and the top of the edge-form is connected back to the decking with restraint straps at approximately 600mm centres using either pop-rivets or self-drilling screws.
Fasteners and Locations
The decking must be secured to the supporting structure in order to avoid movement and excessive deflection during the pouring of concrete. When fixing to a steel support structure, shot fired pins or self-drilling/tapping fasteners should be used. Provide one fastener in each pan at every support. In the case of other support systems, such as brickwork, block work and concrete, the KF57® sheets must be temporarily held in place against wind and other effects until the concrete is poured.
Reinforcement
Place all reinforcement in strict accordance with the structural engineer’s drawings and specification.
Concrete Placement
The specified grade of concrete and any chemical admixtures must be in strict accordance with AS 3600:2018 and the structural engineer’s drawings and specification. The deck must be clear of any excess dirt, grease or debris as this inhibits bonding between the deck and concrete. Ensure that concrete is applied evenly over the decking surface, as mounding of the wet concrete will cause excessive local loading.
Laying KF57®
1. Place the KF57® sheet over the supports ensuring a minimum end bearing of 50mm. If supporting on a brick or masonry wall, provide a separating strip such as malthoid.
2. Engage subsequent sheets of KF57® by locking the larger female rib over the male rib as shown in the diagram below.
