NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings

6

Specification 6 Structural tests for lightweight construction

Specification 6 Structural tests for lightweight construction

This Specification describes tests to be applied to and criteria to be satisfied by a wall system of lightweight construction.

 

This Guide does not address, in detail, every provision in this Specification.
Lightweight construction is more susceptible to damage than other forms of fire protection. It therefore needs protection to preserve its integrity in a fire.
Specification 6 describes a number of tests on walls of lightweight construction which can be used to demonstrate their acceptance as a fire protection system under the Deemed-to-Satisfy Provisions.

A wall system need not be tested in accordance with this Specification for static pressure or impact if it is designed and constructed in accordance with the Deemed-to-Satisfy Provisions of Part B1 to resist the appropriate pressures and impacts defined in this Specification.

 

A wall system need not be tested in accordance with this Specification for static pressure or impact if it is designed and constructed in accordance with the Deemed-to-Satisfy Provisions of Part B1 to resist the appropriate pressures and impacts defined in this Specification.

Tests

(1) Lightweight construction forming—

  1. a wall of a lift shaft and stair shaft; and
  2. an external and internal wall bounding a public corridor, public lobby or the like, including a fire-isolated and non fire-isolated passageway or ramp,

in spectator stand, sports stadium, cinema or theatre, railway or bus station or airport terminal, must be subjected to the tests and must fulfil the criteria set out in (2).

(2) For the purposes of (1), the following tests and criteria apply:

  1. The materials tests of S6C10(a) and the criteria of S6C11(a).
  2. A static test by the imposition of a uniformly distributed load of 1.0 kPa (or its equivalent) in accordance with S6C10(b) and the damage and deflection criteria of S6C11(b) and (c) respectively.
  3. A dynamic test by the fall of the impact bag through a height of 350 mm in accordance with S6C10(c) and the damage and deflection criteria of S6C11(b) and (d) respectively.
  4. The surface indentation test of S6C10(d) and the surface indentation criterion of S6C11(e).

A wall of lightweight construction that is required to be fire-resisting and which bounds a lift shaft, stair shaft, or service shaft, fire-isolated passageway or fire-isolated ramp must be subjected to the following tests and must fulfil the following criteria:

  1. The materials tests of S6C10(a) and the criteria of S6C11(a).
  2. A static test by the imposition of a uniformly distributed load of 0.35 kPa (or its equivalent) in accordance with S6C10(b) and the damage and deflection criteria of S6C11(b) and (c) respectively.
  3. A dynamic test by the fall of the impact bag through a height of 150 mm in accordance with S6C10(c) and the damage and deflection criteria of S6C11(b) and (d) respectively.
  4. The surface indentation test of S6C10(d) and the surface indentation criterion of S6C11(e).

(1) In addition to the requirements of S6C3 and S6C4, a wall system for use in a lift shaft that is required to be fire-resisting must be subjected to dynamic test by the imposition of—

  1. where the lift car speed is 7 m/s or less — 106 cycles of a uniformly distributed load between 0 and 0.2 kPa (or its equivalent); or
  2. where the lift car speed is greater than 7 m/s — 106 cycles of a uniformly distributed load between 0 and 0.35 kPa (or its equivalent) in accordance with S6C10(e) and must fulfil the damage criteria of S6C11(b).

(2) The wall system must be subjected to the static test in accordance with S6C4(b) after the successful conclusion of the dynamic test specified in (1).

An external and internal wall of lightweight construction that is required to be fire-resisting, other than one covered by S6C3, S6C4 or S6C5, must be subjected to the following tests and must fulfil the following criteria:

  1. The materials tests of S6C10(a) and the criteria of S6C11(a).
  2. A static test by the imposition of a uniformly distributed load of 0.25 kPa (or its equivalent) in accordance with S6C10(b) and the damage and deflection criteria of S6C11(b) and (c) respectively.
  3. A dynamic test by fall of the impact bag through a height of 100 mm in accordance with S6C10(c) and the damage and deflection criteria of S6C11(b) and (d) respectively.
  4. The surface indentation test of S6C10(d) and the surface indentation criterion of S6C11(e).

Test Specimens

Testing must be carried out on either—

  1. construction in-situ; or
  2. a laboratory specimen of the construction.

If testing is carried out in-situ, it must be done on that part of the construction least likely, because of the particular combination of the height of the walls, the support conditions and other aspects of the construction, to resist the loads.

If a laboratory specimen is tested, the specimen must span only in the direction corresponding to the height of the wall and testing must be done in accordance with either (a) or (b) below:

  1. The test specimen—
    1. height (or length, if the specimen is tested horizontally) must be identical with the height between supports in the actual construction; and
    2. must be supported at the top and bottom (or at each end if tested horizontally) by components identical with, and in a manner identical with, the actual construction.
  2. If the distance between supports of the actual construction is more than 3 m, then a smaller specimen may be tested but—
    1. the distance between supports must be not less than 3 m; and
    2. forces, reactions and support conditions must be modelled so as to reproduce the behaviour of the actual construction if it were tested in-situ.

Test Methods and Compliance Criteria

Tests must be carried out in accordance with the following:

  1. Material tests — The methods specified for the constituent materials of the construction of the standards adopted by reference in the NCC.
  2. For resistance to static pressure — The provisions for testing walls under transverse load in ASTM E72-15, except that—
    1. support conditions must be as specified in S6C9; and
    2. equivalent load shall mean the quarter-point load that produces the same deflection or central moment as appropriate; and
    3. the timber species nominated in that standard may be substituted with a different species.
  3. For resistance to impact — The provisions for testing wall systems in ASTM E695-03, except that—
    1. the point of impact must be set 1.5 m above finished floor level or 1.5 m above the part of the specimen that corresponds to finished floor level; and
    2. the impact bag must be not less than 225 mm in diameter and not more than 260 mm in diameter and have a mass of not less than 27.2 kg or more than 27.3 kg; and
    3. the mass must be achieved by putting loose, dry sand into the bag and must be adjusted before each series of impact tests; and
    4. where the impact bag and suspension cannot be vertical at the instant of impact on a curved surface or an inclined surface, the height of drop is the net height at the point of impact.
  4. For resistance to surface indentation — The test for resistance to surface indentation must be carried out at three points on the surface of an undamaged sample sheet as follows:
    1. A steel ball of 10 mm diameter with a load of 150 N must be placed gently on the surface of the sheet and allowed to remain in position for 5 minutes.
    2. The ball and load must then be removed and the diameter of each impression of the ball on the surface measured.
  5. For resistance of lift shaft construction to repetitive load — As for (b) except that—
    1. it is sufficient to test one specimen with the pressure applied from the side of the construction on which the lift will operate; and
    2. the load must be applied dynamically at a frequency not less than 1 Hz and not more than 3 Hz; and
    3. equivalent load shall mean the quarter-point load that produces the same central moment as the distributed load.

The wall system or the specimen of it must fulfil the following criteria:

  1. Materials — Materials must comply with the applicable standard adopted by reference in the NCC.
  2. Damage — There must be no crack, penetration or permanent surface-deformation to a depth of more than 0.5 mm or any other non-elastic deformation or fastener failure.
  3. Deflection — Static pressure — Under static pressure the deflection must not be more than—
    1. 1/240th of the height between supports; or
    2. for construction other than a lift shaft — 30 mm; or
    3. for a lift shaft — 20 mm.
  4. Deflection — Impact — Under impact the instantaneous deflection must not be more than—
    1. 1/120th of the height of the wall between supports; or
    2. for construction other than a lift shaft — 30 mm; or
    3. for a lift shaft— 20 mm.
  5. Surface indentation — No impression must be more than 5 mm in diameter.