AS 4422:2016 pdf free download – Playground surfacing-Specifications,requirements and test method

AS 4422:2016 pdf free download – Playground surfacing-Specifications,requirements and test method.
Test specimens or installed areas of the impact-attenuating material under test are struck by an instrumented missile in a defined series of impacts from different drop heights. The signal emitted by an accelerometer in the missile during each impact is processed to yield a severity from the measured impact energy, defined as HIC.
NOTE: See Appendix B. Figure BI.
The HIC of each impact is plotted and h shall he determined as the lowest drop height producing a HIC value of 1000.
2.2 TEST APPARATUS
2.2.1 Test rig
2.2.1.1 General
The test rig shall comprise—
(a) a missile with accelerometer (see Clause 2.2.1.2): and
(b) if using a triaxial (free-fall) accelerometer, a release system (see Clause 2.2.1.3) and length measuring equipment (see Clause 2.2.1.5); or
(c) if using a uniaxial (guided) accelerometer, a guidance system (see Clause 2.2.1.4) and velocity measuring equipment (see Clause 2.2.1.6).
2.2.1.2 Missile and accelerometer
The missilc shall consist of eithcr—
(a) a hemispherical cndcd aluminium alloy missile: or
(b) a spherical shaped missile.
It shall have a diameter of 160 mm ±5 mm, a mass of 4.6 kg ±0.05 kg, with a maximum deviation from the hemispheric surface of 0.5 mm. incorporating an accelerometer as follows:
(i) Triaxial accelerometer for free falling missile, mounted in the centre of gravity of the missile.
(ii) Uniaxial accelerometer for guided missile, aligned to measure in the vertical axis ±5° and located directly above the centre of mass.
The impacting part of the missile between the lower boundary and accelerometer shall be homogeneous and free from voids.
2.2.1.3 Release system
In the case of free-fall impact tests, the release system shall not create a rotation moment or any other forces on the missile, when released.
NOTE: A rotation moment or other forces on the missile would cause additional accelerations after impact in the triaxial accelerometer, leading to an uncontrollable error of the resultant for the vertical measurement.
Each impact shall display the time/acceleration trace and be examined for any anomalies before being processed and evaluated.
NOTES:
1I If high frequency components appear in the signal obtained from a drop lest using the missile dcscribcd in this test method, it is vcry likely that some mechanical fault is present in the apparatus. Check to ensure that no component of the missile is loose, in particular the accelerometer.
2 If high frequency components appear as a consequence of vibrations of the drop test missile. filtration of signals with a standardized t’ilter will be necessary. Measure both with and without the filter and compare the I-Ill’ values.
2.4.6 Material type
2.4.6.1 Loose—fill (particulate) materials
Particulate materials shall be placed in the test frame above the flat rigid substrate and uniformly distributed within the frame, without compaction, to a depth specified by the supplier.
2.4.6.2 Tiles (manufactured prior to installation)
For testing tiles, a minimum four tiles with a minimum total dimension of 1 m x I m shall be installed on a flat, rigid substrate according to the manufacturer’s instructions, including all connecting and site fixing elements used for installation in the playground.
2.4.6.3 Unitary surfaces intended to he manufactured on-site
For testing surfacing intended to he manufactured On-Site a minimum one test specimen shall be prepared without seams or joints with a minimum total dimension of 1.0 m x 1.0 m and placed on a rigid substrate in accordance with the manufacturer’s instructions.
2.4.6.4 Unitary surfaces consisting of multiple layers
For products intended to be laid over another layer, the entire system (surfacing with under layer) shall be tested on the flat rigid substrate and reported as a composite product.
NOTE: Substrates other than the fiat, rigid substrate are likely to contribute to the impact attenuation of the material being tested.