Austral Masonry NSW Page 1 AustraLite Fire Resistance Levels In 2008 - 2009, a series of fire tests were done on what is now known as AustraLite masonry. When calculated to the requirements of AS3700:2011, Section 6, they were proved to achieve much higher Fire Resistance Levels (FRLs) than standard concrete masonry units: Structural Adequacy FRL: The Slenderness ratio (S rf ) of a proposed wall is calculated by the formulae in AS3700, Clause 6.3.2.2 factoring the wall’s spanning height/length, thickness and which edges are restrained. The maximum S rf s for AustraLite are: 60 minutes: 22.93 Loadbearing 27.83 NON-Loadbearing 90 minutes: 21.31 Loadbearing 27.83 NON-Loadbearing 120 minutes: 20.16 Loadbearing 26.32 NON-Loadbearing 180 minutes: 18.54 Loadbearing 23.30 NON-Loadbearing 240 minutes: 17.39 Loadbearing 21.16 NON-Loadbearing The graphs on pages 4 to 14 show the AS3700 formulae for each of these conditions. Integrity FRL: The NON-Loadbearing test (EWFA 2345.600) of a 90mm wall with S rf = 25.83 achieved a 240- minute Integrity FRL. According to AS3700, Clause 6.4.3, NON-Loadbearing AustraLite masonry with t > 90mm and S rf < 25.83 will achieve a 240-minute Integrity FRL. S rf = 25.83 S rf = 25.83
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Austral Masonry NSW Page 1
AustraLite Fire Resistance Levels In 2008 - 2009, a series of fire tests were done on what is now known as AustraLite masonry. When calculated to the requirements of AS3700:2011, Section 6, they were proved to achieve much higher Fire Resistance Levels (FRLs) than standard concrete masonry units:
Structural Adequacy FRL: The Slenderness ratio (Srf) of a proposed wall is calculated by the formulae in AS3700, Clause 6.3.2.2 factoring the wall’s spanning height/length, thickness and which edges are restrained. The maximum Srfs for AustraLite are: 60 minutes: 22.93 Loadbearing 27.83 NON-Loadbearing 90 minutes: 21.31 Loadbearing 27.83 NON-Loadbearing 120 minutes: 20.16 Loadbearing 26.32 NON-Loadbearing 180 minutes: 18.54 Loadbearing 23.30 NON-Loadbearing 240 minutes: 17.39 Loadbearing 21.16 NON-Loadbearing
The graphs on pages 4 to 14 show the AS3700 formulae for each of these conditions.
Integrity FRL: The NON-Loadbearing test (EWFA 2345.600) of a 90mm wall with Srf = 25.83 achieved a 240-minute Integrity FRL. According to AS3700, Clause 6.4.3, NON-Loadbearing AustraLite masonry with t > 90mm and Srf < 25.83 will achieve a 240-minute Integrity FRL.
Srf = 25.83 Srf = 25.83
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The Loadbearing test (EWFA 2345.400) of 110mm AustraLite with Srf = 21.14 achieved a 240-minute Integrity FRL Loadbearing AustraLite walls with t > 110mm & Srf < 21.14 achieve a 240-minute Integrity FRL.
Srf = 21.14 Srf = 21.14
Loadbearing 90mm AustraLite is calculated using the deemed-to-satisfy provisions of Clause 6.4.2
Insulation FRL: AustraLite masonry requires material thicknesses of: 70mm to achieve 60 & 90-minute FRLs 80mm to achieve a 120-minute FRL 102mm to achieve a 180-minute FRL and 120mm to achieve a 240-minute FRL All AustraLite masonry units have a material thickness greater than 80mm, which gives them a minimum 120-minute Insulation FRL, calculated as per AS3700:2011, Clause 6.5.4(b) (ii). The highest FRL requirement is 240-minutes. Austral achieves this by reducing the core size of 15-01 and 20-01 blocks to give them a material thickness greater than 120mm as per AS3700, Clause 6.5.2. To distinguish these from the 120-minute rated blocks, their code numbers are 15-401 and 20-401. The Insulation FRL for each block is shown in the following bar chart.
INSULATION FRL (minutes) Code Nos.
60 90 120 180 240
10-01; 10-31; 15-01; 20-01; 15-421 & 20-421
15-421; 15-48 & 15-91 when core-filled
11-162; 11-119; 11-76 & 12-01
15-401 & 20-401
20-421; 20-48; 20-91; 30-48 & 30-91 when core filled
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How to use the Structural Adequacy charts: The first set of graphs (pages 4 to 9) is for NON-Loadbearing masonry. The 2nd set (pages 10 to 14) is for Loadbearing masonry. Page 15 is for partially reinforced masonry which increases the maximum Srf to 36. Find the appropriate page with the required FRL: 60, 90, 120, 180 or 240 minutes. Next, find the graph with the same restraint conditions as your proposed wall. Finally, plot the intersection of your wall’s height and length on the appropriate graph. The thickness required is represented by those lines clear of the intersection point. Note: All masonry must be designed for Robustness (AS3700, Part 4.6). In some cases, the Robustness requirement overrides the FRL limits. Where this occurs, the pale Robustness graph-line changes to the darker colour of the FRL line. Some walls, particularly those without ends restrained, are governed by other loads (e.g. Vertical, Bending, Robustness, Earthquake etc.) Please check this and any other loads with your engineer.
Disclaimer: Please note: It is the designer’s responsibility to allow for the effects of control joints; chases; openings; the strength and stiffness of connectors & supports, in addition to consideration of loads and masonry properties.
