Specifications

STANDARD SPECIFICATION - BUILDINGS
DPI REFERENCE TEXT - APRIL 2009
PAGE 9
CONCRETE CONSTRUCTION
3. CONCRETE CONSTRUCTION
3.1 GENERAL
Cross reference
Refer to the General Requirements section for
termite protection.
Standards
Concrete structures generally: To AS 3600 & AS
3610.
Plywood Formwork: To AS 6669.
Ground slabs and footings: To AS 2870 where
appropriate.
Reinforcement: To AS/NZS 4671.
Deformed Ribbed Bar: Normal ductility class,
strength grade 500 MPa, unless otherwise noted.
Round Bars: Normal ductility class, strength grade
250 MPa.
Reinforcing Mesh: Deformed ribbed, low ductility
class, strength grade 500 MPa.
3.2 INSPECTION
Notice - Witness Point
Witness Point: Give sufcient notice so that
inspection may be made at the following stages:
• Termite barrier and lm underlay installed.
• Completed formwork, and reinforcement, cores
and embedments xed in place.
• Commencement of concrete placing.
• Before core lling masonry.
3.3 TESTS
Compressive strength – Hold Point
Sample, test, and assess: To AS 3600 and AS
1379.
Hold Point: Agree to the method of strength
assessment prior to ordering concrete. Production
assessment may be used if applicable and if the
project is registered with the concrete producer for
dissemination of production assessment statistics.
Other quality parameters
Sample, test and assess: To AS 1379 Section 5
using a NATA registered testing authority.
Slump: Test at least one sample from each batch
before placing concrete from that batch in the work.
Take the samples at the point of discharge on site.
Rejection: Remove rejected concrete from the site.
3.4 GROUND SLAB VAPOUR BARRIER
General
Provide a vapour barrier under slabs on ground
including integral ground beams and footings.
Standard
Vapour barriers and damp proof membranes: To
AS 2870.
Proprietary Item: Fortecon
Installation
Lay over the base, lap joints 200 mm and seal the
laps and penetrations with waterproof adhesive
tape. Seal punctures and tears with waterproof
tape before pouring concrete.
3.5 REINFORCEMENT
General
Provide reinforcement, including tie wires, plastic
support chairs, spacers and accessories.
Identication: Supply reinforcement which is readily
identiable as to grade and origin.
Dowels
Round Bars, each dowel in one piece, straight, with
square cut ends free from burrs. Apply two coats of
bitumen emulsion to half the length of the dowel at
one end. Embed the unpainted half of the dowels in
the concrete placed rst.
Minimum lap
Splice as follows:
• Mesh generally: 225 mm.
• Trench mesh: 500 mm.
• Bars: Greater of either 500 mm or 25 x bar
diameter.
• Strip footing intersections and corners: For full
width of intersecting reinforcement.
Minimum cover
Unprotected by membrane on ground or external
surfaces: 40 mm.
Protected by membrane on ground: 30 mm.
Internal surfaces: 20 mm.
Footings: 50 mm
Aggressive soil or salty environment: 65 mm.
3.6 EMBEDDED ITEMS
Placing and xing – Hold Point
Hold Point: Fix cores and embedded items to
prevent movement during concrete placing. Obtain
approval before cutting reinforcement or displacing
reinforcement from its required location.
Tolerances on placement
Maximum deviation from correct positions:
• Embedded items generally: + 10 mm.
• Fasteners including, anchor bolts: + 3 mm.
• Anchor bolt groups for structural steel: To AS
4100 clause 15.3.1.
Corrosion protection
Galvanized ferrous xings (other than stainless
steel) to AS/NZS 4680 or AS 1214. Passivate
galvanized surfaces to be embedded in concrete by
dipping in 0.2% sodium dichromate solution.
3.7 CONCRETE
Pre mixed supply
Standard: To AS 1379, by the batch production
process.
Maximum slump: 80 mm.
Specifications March 2009.indd 9 11/03/2009 11:47:09 AM