<?xml version="1.0" encoding="UTF-8" standalone="no"?><?Xpress productLine="ncc-clause" ?><clause author="Kieran O'Donnell" dateTime="2021-02-24T14:48:44" id="_643b741a-4f97-4828-b522-24a93d095c37" outputclass="ncc-clause" type="insert"><meta><facet building="Class 2"/><facet building="Class 3"/><facet building="Class 4"/><facet building="Class 5"/><facet building="Class 6"/><facet building="Class 7a"/><facet building="Class 7b"/><facet building="Class 8"/><facet building="Class 9a"/><facet building="Class 9b"/><facet building="Class 9c"/><facet climate="Climate zone 8"/></meta><sptc>4.2.10</sptc><title id="_8fb689ff-ef7c-41ac-88f9-123bf24b83d4">Concrete</title><archive-num>2019: 3.2.3.1</archive-num><clause-variation href="/tmp/QppServer/Publishing/5e2c1f63-e589-4ce1-95e8-5c3e286a7aff/4576_0.5.0.xml" variation="SA" variation-type="REPLACE">SA REPLACE Clause</clause-variation><subclause id="_f7d220ab-0ec3-4cfa-8e60-1f43259ea9ab" outputclass="subclause"><title id="_f96b0fff-3219-4d27-ac7a-3ed1230ab6f3">SubClause</title><num>1</num><p>Concrete must comply with the following:</p><ol outputclass="alpha"><li id="_dcf3d317-2131-4976-aae7-fdba750c847c">Concrete must comply with AS 3600; and—<ol><li>have a strength at 28 days of not less than 20 MPa (denoted as N20 grade); and</li><li>have a 20 mm maximum nominal aggregate size; and</li><li>have a nominal 100 mm slump.</li></ol></li><li id="_e732494b-d0e5-439f-9574-308e53d2ff90">Water must not be added to the mix to increase the slump to a value in excess of that specified.</li><li id="_56e7ffb0-8831-486c-abbd-e14d13b2d372">Concrete must be placed, compacted and cured in accordance with good building practice.</li></ol></subclause><callout id="_803ce2a3-ec02-4317-b9f4-eddbc22cd6fd"><callout-type ncc-info-type="info"/><ul outputclass="numbered"><li>Complete discharge of the concrete from the truck should be made within one and a half hours of initial mixing with water unless a suitable retarder has been specified.</li><li>Compacting concrete by vibration removes air pockets and works the concrete thoroughly around reinforcement, service penetrations etc. and into corners of formwork to increase durability and resistance to termite infestation and salt damp attack. Care should be taken not to over-vibrate. The finishing and curing of slab edges provides an improved edge finish which is resistant to edge dampness.</li><li>Care should be taken when using chemical curing methods, because some products may not be compatible with adhesives used to fix surface finishes to the slab.</li></ul></callout></clause>