Weier Group geotech · MCU17/0523

APPENDIX 1: CONSTRUCTION SPECIFICATION FOR SLABS ON GROUND

1. Site Preparation

All vegetation and top soil that contains grass or trees roots and any rubbish shall be removed from the site prior to the commencement of
construction. Following stripping of the site, the building platform is to be compacted and proof-rolled to ensure that no loose material is present
on the surface. If necessary, any material which cannot be adequately compacted shall be removed, then replaced with a suitable material
which can be compacted to the standard specified.

If the site is to be “Cut-and-Filled”, then the construction of the footing beams and the placement of the fill material shall be in accordance with
the requirements of Appendix 2: Specification for Placement of Fill Material.

The foundation under the floor shall be poisoned against termites in accordance with the Tequirements of the Local Authority and the Building
Code of Australia.

2. Polythene Membrane
A layer of high-impact polythene sheeting shall be provided under all floor slabs. The membrane shall be continuous under the slab and
internal footing beams and shall be terminated at the edge beams as indicated on the Footing System drawings. The membrane is to be taped
at all joints with a 200 mm minimum overlap and shall be loosely place in the excavated footing trenches to allow the sheeting to conform totally
to the width and the depth of the beam once the concrete is placed.

3. Reinforcement

All steel reinforcement shall conform to the requirements of AS1302 and AS1304. The reinforcement shall be supported on plastic bar chairs to
ensure that the specified cover to all sides is achieved and maintained during placement and compaction of the concrete.

Minimum laps for reinforcement shall be as follows:

Slab Fabric - 225 mm minimum overlap of “cross-bars” at all edges (r 400 overlap without any “cross-bars”)
Trench Mesh - 500 mm splices in all footing beams.

- Laps at intersections shall be shown on the Footing System Drawings.
Reinf.Bars - 500 mm splices in all footing beams

- Provide “L” bars at all beam intersections with min. 500 mm laps to each leg.
Cover to reinforcement shall be as follows:

- 25 mm to the upper face of internal slabs.

- 40 mm to the upper face for external exposure.

- 30 mm to the polythene membrane in contact with the ground.

- 40 mm to unprotected ground. *

4. Alternative Reinforcement Details

Slab Mesh - Deformed Wire Fabrics equivalent to LSDF 752 by “Neumann Steel” may be substituted for F82 mesh
(similarly, LSDF 652 Deformed Wire Fabric may be substituted for F72 Mesh).
Ligatures - 10mm diameter Deformed Wire ligatures by “Neumann Steel” (FSY = 500 MPa), at 1000 mm max crs.

-  Y12 deformed bars at 1000 mm crs.
5. Concrete

Concrete shall have a minimum 28 day compressive strength of 20 MPa, with an 80 mm slump and a 20 mm maximum nominal aggregate size.
All concrete must be well compacted to ensure that all entrapped air is removed and that the concrete is worked around the reinforcement and
into all corners. This is easily achieved by the use of mechanic al vibrators.

In order to minimise shrinkage cracking of the concrete, the slab may be “cured” to retain the moisture in the concrete for as long as possible.
The most convenient method of curing is to use an approved spray-on curing compound which is applied after the concrete has been placed
and levelled and has reached its initial set. The curing compound allows continued access to the slab during the curing process, however, care
must be taken to avoid damage to the membrane resulting from excessive construction traffic.

6. Thickenings under Bracing Walls

Slab thickenings under bracing walls have not been specified, as this information requires that an assessment be made of the wind loading on
the structure, which is outside the scope of this report. It is the responsibility of the designer of the structure to specify the location and type of
all bracing walls. Where a bracing wall is fixed to the floor slab with a bolt, then the slab shall be locally thickened to 150 mm thick for a distance
of 150 mm on all sides of the bolt.

7. Shrinkage Control

Long Slabs(<25m) -  F82 reinforcing mesh should be provided for slabs over 18 metres in length if shrinkage cracking is to be
minimised. Alternatively, Deformed Wire Fabrics equivalent to LSDF 752 by “Neumann Steel” may be substituted
for F82 reinforcing mesh (similarly, LSDF 652 Deformed Wire Fabric may be substituted for F72 reinforcing mesh).

Re-entrant Steel - Additional reinforcement (2 metres in length) shall be place diagonally across the potential crack at all re-entrant
corners, comprising either:

- 2 layers of 3— 8TM trench mesh, or
- 1 layer 3-11TM trench mesh, or
- 3 —Y12 reinforcing bars.

Placement of Tiles - Where floor slab is to be tiled, in order to minimise the effects of shrinkage, the following recommendations are

made:

- F92 slab mesh (or equivalent) should be provided in the area to be tiled.

- Cure the slab by keeping it wet (or sealed) for at least 7 days.

- Placement of tiles should be delayed for as long as possible (preferably for at least 3 months)
- Use a rubber-based adhesive when laying the tiles.