Understanding Changes in AS3600-2018 Amendment 2 Concrete | Stay up-to-date with the latest updates to the AS3600-2018 Amendment 2 concrete design standard. Explore the key revisions, additions, and implications for concrete design and construction in Australia. Enhance your knowledge and ensure compliance with the updated guidelines.
A number of significant updates have been made with AS3600:2018 Amdt 2, whose key effects are on the spacing and quantity of shear fitments / ligatures required.
Upper limit shear strength (Vumax) has been reduced by 10% in equation 220.127.116.11(1)
Factor kv (simplified method) increases the concrete shear capacity (Vuc) by up to 50% from Amendment 1, in particular for thinner depth sections without reinforcement. Previously a limit of kv = 0.10 was placed for any beam where minimum shear reinforcement was not satisfied or no fitments were provided. This has now been increased to kv = 0.15. Refer Cl 18.104.22.168(a)
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The minimum reinforcement spacing is now relaxed for beams with low shear force. Where V* <= ΦVu,min, the fitments may now be spaced at 500mm or 0.75 × D, whereas previously 300mm or 0.5 × D limit was imposed under all circumstances apart from very large beams.
For a short column satisfying, L < 5 × depth, Amendment 2 has introduced minor changes to the max allowable fitment spacing to reflect the actual fitment strength. spacing = √(fsyf/500) × 24×d instead of spacing = 24×d previously in accordance with Cl 14.5.4(b)
For beams of depth > 300mm, shear fitments are now required even when V* does not exceed ΦVuc. An additional factor ks has been added factoring down the upper limit shear force that may be taken without adding fitments in Eq Cl 22.214.171.124(1).
Dc now renamed to b (smaller column cross-sectional dimensions). Refer Cl 1.7.
Ks now renamed to ks (Beam Depth Factor to Determine Reinforcement Required). The definition of Ks in Cl 1.7 has not been updated in Amendment 2 from its previous version. It is believed that this definition should be further expanded in future revisions to reflect its use in Cl 126.96.36.199(1).
The above is not a comprehensive list of Amendment 2 changes. However, they do reflect all the changes that are relevant to calculations performed in ClearCalcs. ClearCalcs concrete calculators utilise the Simplified Method for calculating kv and θv in compliance with Cl 188.8.131.52. Therefore the Amendment 2 updates for the "General Method" Cl 184.108.40.206 are not listed above.
ClearCalcs has updated its calculator for consistency with this new amendment. ClearCalc's concrete calculators affected by Amendment 2 changes are:
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