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. ClearCalcs has updated its calculator for consistency with this new amendment.ClearCalcβs concrete calculators affected by Amendment 2 changes are:
Capacity Reduction Factor (Bending Moment with compression)
Table 2.2.2 (d) has changed the Ξ¦β factor to be equivalent to Ο0β=0.65ΓkΟ. There is a minor impact on the reduction factor where columns are slender or where GQββ€0.25, refer to calculations for kΟ.
Upper limit shear strength Vu,maxβ has been reduced by 10% in Equation 8.2.3.3(1).
Factor kvβ (simplified method) increases the concrete shear capacity Vucβ by up to 50% from Amendment 1, in particular for thinner depth sections without reinforcement.
Previously a limit of kvβ=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 kvβ=0.15. Refer Clause 8.2.4.3(a).
The minimum reinforcement spacing is now relaxed for beams with low shear force. Where Vββ€ΟVu,minβ, the fitments may now be spaced at 500mm or 0.75ΓD whereas previously 300mm or 0.5ΓD limit was imposed under all circumstances apart from very large beams.
For a short column satisfying L<5Γdepth, Amendment 2 has introduced minor changes to the max allowable fitment spacing to reflect the actual fitment strength spacing=500fsyfβββΓ24Γd instead of spacing=24Γd previously in accordance with Clause 14.5.4(b).
For beams of depth>300mm, shear fitments are now required even when Vββ€ΟVucβ. An additional factor ksβ has been added factoring down the upper limit shear force that may be taken without adding fitments in Clause 8.2.1.6(1).
Dcβ is now renamed to b (smaller column cross-sectional dimensions). Refer Clause 1.7.
Ksβ is now renamed to ksβ (Beam Depth Factor to Determine Reinforcement Required). The definition of Ksβ in Clause 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 Clause 8.2.1.6(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 kvβ and ΞΈvβ in compliance with Clause 8.2.4.1. Therefore, the Amendment 2 updates for the βGeneral Methodβ in Clause 8.2.4.2 are not listed above.
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