Cover Calculator

Name: Reinforcement cover for fire (AS 3600:2018) - Slabs and Beams
Brand: PROMAXA
SKU: 6866ea9e-5327-4122-a7a4-6e6ff31f69fe

Provided by Promaxa, this calculator assists engineers and specifiers in determining appropriate reinforcement cover for concrete elements, accounting for durability exposure conditions and fire resistance requirements in accordance with AS3600:2018

Required axis distance

a_m = 0 mm

Required cover for fire

c_f_i_r_e = 0 mm

Reinforcement cover for fire (AS 3600:2018) - Beams

This calculator determines the minimum reinforcement cover and axis distance required to achieve a specified Fire Resistance Period (FRP) for beams (Cl. 5.4) and slabs (Cl. 5.5) in accordance with AS 3600:2018 Section 5.

Workflow:

Select element type and support condition.
Select FRP.
For beams, enter beam width b.
Enter the bottom bar diameter (and stirrup/ligature diameter for beams).

The required axis distance a is taken from the AS 3600 tables and the cover is computed as c = a_m - d_b/2 - d_s.

Where the required FRP or beam width falls between tabulated values, linear interpolation is permitted per Cl. 5.3.2 and is applied automatically to the displayed lookup tables.

Fire resistance periods (FRPs) for structural adequacy for simply supported beams - Figure 5.4.1(A) AS 3600:2018

The table is not uploaded or the values for the variables: do not match table records.

Required cover for fire

Not Available

Notes and limitations:

The cover from this calculator is for fire resistance only. The governing cover is the larger of cover for fire (Section 5) and cover for durability (Section 4) per Cl. 4.10.1.
For prestressing tendons, the axis distance shall be increased by 15 mm for strand or wire and 10 mm for prestressing bars per Cl. 5.3.3.
For beams with only one layer of bottom reinforcement, the side cover to the corner bars shall be increased by 10 mm except where the beam width is greater than that given in Combination 4 (Notes to Tables 5.4.1(A) and 5.4.1(B)).
Linear interpolation between tabulated values is permitted per Cl. 5.3.2 and is applied to the displayed beam tables.
Out of scope of this calculator: beams exposed to fire on all four sides (Cl. 5.4.2 - apply additional rules to b and a); two-way ribbed slabs Tables 5.5.2(C) and 5.5.2(D); columns (Cl. 5.6); walls (Cl. 5.7); FRP enhancement by added insulating materials (Cl. 5.8).
Walls/columns and other members may require performance-based assessment per Cl. 5.3.1 if outside the tabular limits.