What is Artificial Grass?
Artificial grass is a man made artificial surface manufactured from synthetic materials made to look like natural grass. It is most often used in areas for sports that were originally or are normally played on grass. However, It's now being used on residential lawns and commercial applications as well. The main reason is the little maintenance required. Artificial grass resists heavy use (such as sports) a lot better than natural grass, and requires no irrigation. The artificial grass then has silica sand and rubber particles mixed deep into the grass fibres to hold the fibres upright and give a nice soft feel to walk on. We use only the best infills such as Tyre Crumb. They are an Australian owned and operated company using Australian made recycled rubber crumbs.
Where can i get Artificial Grass?
Artgrass.com has a head office located in Melbourne Australia. You are more then welcome to come over to get any artificial grass or discuss your grass requirements and talk about specifications. We can also service all states Australia wide. We always encourage and use local installers for our artificial grass works to keep installation costs at a low giving money back into your local community.
When can i get some Artificial Grass?
We operate during normal business house 9am - 5pm Monday - Friday. Your can come visit us anytime then. Please note that DIY self installations for artificial grass or small residential and commercial jobs can most likely be picked up from our Melbourne head office same day. Just simply drop in or contact us for all types of artificial grass surfaces and availability.
How to Install Artificial Grass?
Easy Done! Self installations of artificial grass are as easy as 123!
Simply visit our artificial grass installation section for a commercial view on how to install larger projects. Small artificial grass installations are quite easy and we encourage DIY (do it yourself) most of the time. Don't forget, all artificial grass customers receive a handy DIY installation manual with easy to follow instructions for your residential landscaping, pathways and any other grass applications.
Please see below for a detailed description of our artificial grass test reports from the university of South Australia.
The Artificial Grass Safety Surface Test Report
for Artgrass.com - Artificial Grass Surfaces.
The EVA Impact Surface Tile (40mm) under
Sand-filled Artificial Grass with pile height of 40mm
The School of Mechanical Engineering
The University of Adelaide, South Australia.
1.0 The Executive Summary of the inital Test.
Artgrass.com supplied an artificial grass surfacing product that consists of a forty millimetre (40mm) layer of EVA foam covered by a surface layer of sand-filled artificial grass (pile height of 40mm). Tests were conducted on the impact absorption properties of this product supplied according to the impact test requirements of the Australian Standard: AS4422:1996, when assembled together in the manner specified by the manufacturer. The impact test result for the product sample is listed in Table 1 below.
TABLE 1 = Critical Fall Height for the product configuration tested.
The Product Combination (Nominal Combined Thickness)
The Impact Surface Tile EVA (40mm) under
The Sand-filled Artificial Grass (40mm)
The Critical Fall Height (m) = 1.6m
2.0 The Introduction to the required tests outlined.
The impact absorption properties of a 40mm EVA layered foam material when covered by a layer of sand filled artificial grass (supplied by Artgrass) was measured according to the impact test requirements specified by the Australian Standard AS/NZS 4422:1996. The base-layer of EVA layered foam consisted of 2 individual 20mm layers bonded together with adhesive glue. The layer of artificial grass (with a height pile of 40mm) rested (un bonded) onto the EVA foam surface. A 14 kilogram bag of sand (supplied by the manufacturer) was distributed
evenly over the area of the test piece, of size: 1 metre × 1metre. The depth of the sand in the pile of the artificial grass was approximately between 8-12 millimetres.
This testing involved dropping a 5 kilogram anatomically-shaped aluminum form head from specified heights and measuring the deceleration of the head form as it strikes the sample tests. The severity of the impact is then measured in terms of the Head Injury Criterion (HIC).
The Australian Standard AS/NZS 4422:1996 concentrates on a method for measurement of HIC, which indicates the deceleration impact on the brain.
It does not indicate the possible injury potential to other parts of the body.
The HIC values set in the standard are those in which, if exceeded, are likely to result in injury to the brain and body. It should alsobe noted that although the standard stipulates that a HIC value of 1000 (or a deceleration value of 200 g) will
determine the critical artificial grass fall height, this does not have widespread agreement.
3.0 The Referenced Documents for this Testing
The documents that are pertinent to this report are:
• The Australian Standard AS 2512.1:1996, “Methods of testing protective helmets”.
• The Australian Standard AS/NZS 4422:1996, “Playground surfacing - Specifications, requirements and test method”.
• The International Standards Organization ISO 6487, “Road vehicles-measurement techniques in impact tests - Instrumentation”.
The equipment that was used to perform the impact testing is outlined below:
The Drop Rig: This drop rig (testing model) is a portable stand that is used to raise the head form. A pin is then
released which allows the head form to fall unguided onto the artificial grass sample. The height the head form is raised then measured with a vertical measuring tape between the upper surface of the sample and the lowest point of the hanging head form model.
The Headform: The headform is made from an anatomical shape that complies with the J-Type headform from AS 2512.1. It has a mass of 5.1kg. A tri-axial
accelerometer (Endevco 7268C-2000) is mounted at the centre of gravity of the headform.
The frequency range of the accelerometers is from 0-1000Hz. This complies with channel class 1000 of ISO 6487. A cable then connects the tri-axial accelerometer to the strain gauge amplifiers.
The Strain Gauge Amplifiers: This is a 3-channel Endevco Model 136 DC strain gauge amplifier and configured for fullbridge circuit configurations.
The High precision balancing resistors are used to convert the half-bridge accelerometers into a full-bridge circuit. Anti-aliasing filters (at 10kHz) are used for each channel.
The Recording Equipment: The output from the strain gauge amplifiers is connected to an analog to digital (A/D) converter board inside a notebook portable computer or laptop. The A/D board samples at 20.0kHz. The collection of artificial grass results data is then triggered automatically based on the starting point of an impact on to the artificial grass test sample as determined from the constant monitoring of a selected channel
value.
The data acquisition procedure has a pre-trigger capability, such that the data is
then collected over a period of time spanning from just before the impact to just after the impact to the artificial grass surface. A sine wave at 200Hz is supplied to one of the A/D channels to provide a check that the sampling rate is then accurate.
The Artificial Grass Product Test Sample: The EVA foam undersurfacing material underneath the artificial grass surface was supplied in the form of two separate 20mm layers of EVA foam tiles pre-bonded together by the manufacturer. The
interlocking edges of the different tile layers were positioned so that these did not correspond between the different layers. Overall, the tile pieces in each layer were glued together (by the manufacturer), with a total size of 1m × 1m or 1m2. This was positioned flat against a concrete floor substrate. The layer of artificial grass surface (with a pile height of 40mm) rested (un bonded) onto the EVA foam surface.
All testing of the artificial grass surface was conducted at the Thebarton Campus of the University of Adelaide in a laboratory environment using all of the above mentioned equipment and apparatuses.
The testing method follows the Australian Standard AS/NZS 4422:1996. In general terms, the artificial grass test sample to be tested was placed on a concrete floor substrate beneath the drop testing rig, the J-type headform was released from various heights and the deceleration of the headform was measured as it struck the test sample. The critical fall height on to the artificial grass test sample is then determined as the height when the Head Injury Criteria (HIC) equals 1000.
where a = the dimensionless ratio of the deceleration experienced by the headform to the deceleration due to gravity (in g).
t2 , t1 = instant of time during the impact, chosen such that HIC is maximized, where t2 > t1.
The critical fall height is the height at which the HIC equals 1000 (or deceleration equals 200 g), rounded down to the nearest 10cm, as specified in AS/NZS 4422:1996.
The artificial grass test procedure is listed below:
1. Prior to testing the impact absorbtion onto the artificial grass surface, the manufacturer’s calibration values for the tri-axial accelerometer are checked by aligning each axis in a vertical direction so that a voltage measurement can be obtained for positive and negative accelerations due to unrestrained gravity force.
2. The acceleration measurement obtained using the instrumented headform is verified by dropping it onto a standard rubber mat, both before and after testing, to ensure consistency and accuracy of data measurement and recording.
3. The artificial grass surface test sample is placed beneath the headform ready for the drop rig.
4. The headform is raised and held in position. The vertical height between the artificial grass surface test sample and the lowest part of the headform is measured with a vertical tape measure.
5. The headform is released and is allowed to fall unguided and strikes the test sample. The collection of data on the A/D board is triggered based on the beginning of the impact event. Data is collected from just before to just after the impact event onto the artificial grass surface.
6. The data is analyzed from the impact to the artificial grass to determine the HIC value and Maximum g value for the drop test.
7. Steps 4-6 are then repeated on the artificial grass surface so that a HIC value is obtained for each of four separate heights at the same location on the grass test sample. The heights are then selected so that HIC values are determined below 1000, close to 1000 and above 1000 (or alternatively, deceleration values below 200 g, close to 200 g and above 200 g).For some cases with the present product combinations, it was found necessary to drop the headform a number of consecutive times at the artificial grass surface prior to beginning the test measurements.
8. The headform impact on the artificial grass test sample is moved to a new position. A total of three separate artificial grass test positions are selected for surfacing materials incase of any defects in manufacturers outcome. The test positions for artificial grass surfaces correspond with one location in the middle of the tile surface, one location on the join between two tiles, and one location on the join between all four tiles.
9. The graphs are drawn of the HIC values versus the drop height. The critical fall height for the grass surface is determined by the height at which the HIC value equals 1000 (or deceleration equals 200 g), rounded down to the nearest 10cm.
The artificial grass surface samples were tested at the locations shown in the Test Sheets in the Appendix
Note: For this EVA foam product sample tested, the magnitudes of the impact results over the first twenty drops (at any particular location) were found to be steadily increasing. Since the impact performance of the surfaces during these initial drops were generally non-repeatable, it is deemed not appropriate to include these initial results among those to be considered for the AS4422:1996 standard. They do not provide a good indication of the longer-term (repeatable) performances of the foam under artificial grass surfacing surfaces, and are generally not included on this basis. The impact test results measured after this initial “conditioning” process were found to be reasonably consistent and repeatable within acceptable limits to the artificial grass..
5.1 The General Comments to Testing the Artifcial Grass Sample:
The sample of the “EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass with a pile height of 40mm fibre product tested consists of a layer of sand-filled artificial grass (pile height: 40mm, sand in-fill height: 8-12mm) resting on a 40mm base-layer of EVA foam. With each consecutive impact onto the artificial grass surface, the magnitudes of the impact results measured are found to vary significantly. The variations of the impact magnitudes over twenty consecutive impacts onto the artificial grass surface at a single location (from a constant height of 1.6m).
Figure 2: An example of the degradation of impact performance over 20 consecutive
headform drops (height: 1.6m) at the same location on the product sample.
When assessing the likely and foreseeable long-term impact attenuation performance of the “EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass witha pile height of 40mm product according to Australian Standard AS4422:1996, it is critical to consider the fact that the impact performance of the surface appears to degrades considerably over the first twenty consecutive impacts at the same location (up to 56% as illustrated in Figure 2). It is clear that the impact absorption characteristics of the artificial grass surface change within these initial impacts onto the surface, which are of a magnitude as required by the standard AS4422:1996.
This is due to the combination of displacement of sand material from the artificial grass surface pile at the impact location, and the degradation of the impact absorption properties of the EVA foam underneath. Therefore, any assessment of the surface impact absorption characteristics within the first number of drops on the surface (at any location) would not be repeatable, and may not accurately or reasonably reflect the expected longer-term impact performance of the
artificial grass surfacing.
To obtain an acceptable level of reproducibility for the impact test results for measurement according to AS4422:1996 , it was found necessary to simulate wear and ageing factors introduced by initial repeated impacts on the artificial grass product (caused by the impact compression of the EVA layered foam).
Therefore, consecutive impacts (at least twenty drops at each test location) were performed on the artificial grass to produce results of acceptable repeatability for measurement according to the standard. Within reason, the measured impact magnitudes appear to exhibit a more higher level of repeatability in terms of the impact magnitude measurements after the first twenty consecutive drops onto the artificial grass surface (from 1.6m).
It's possible that the initial head form impact degradation represents an initial “wearing-in” period, where as the performance of the EVA foam tiles may degrade slightly over the initial period of use, especially in areas associated with high impact traffic flow and fall like underneath a fire pole landing area or just general landing areas of all climbers and stairs. However, the compressibility of the EVA layered foam under high impact does suggest a shorter product life span than more commonly used rubber under surfacing materials. The product should be either replaced (or retested
on-site) if there appears any sign of surface compression, wear or dimpling due to continuing high impacts, to ensure continued performance of the surfacing near the critical fall height determined in these tests.
5.2 The Test Results: “EVA Impact Surface Tile (40mm) under Sand-filled
Artificial Grass with a pile height (40mm)”
According to Artgrass, the “EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass pile height (40mm)” is described as follows:
“The top-coat surface layer consists of a layer of artificial grass surface (pile height: 40mm), in-filled with sand (provided by the manufacturer) to an even depth of approximately 8-12mm. This rests unbonded onto the 40mm thick base layer, which is made from two separate layers of 20mm interlocking EVA foam tiles, bonded together.”
The critical fall height for the “EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass Surface (40mm)” under surfacing sample is 1.6m.
6.0 Conclusions
The testing of the ‘EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass Surfacing with a pile height of 40mm’ product supplied by Artgrass - Artificial Grass Surfaces was undertaken according to the requirements of the Australian Standard: AS/NZS 4422:1996. The outcome of this testing resulted with the critical fall height (shown below in Table 3) for the product listed.
The Artificial Grass Safety Surface Test Report: “EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass (40mm)”
Prepared by MECHTEST: 1st December 2008 for Artgrass.com
The Introduction to the Test Results.
AS/NZS 4422:1996 specifies testing requirements to determine the critical fall height for safety surfaces. The critical fall height is determined by installing the artificial grass safety surface as specified by the manufacturer and determining the fall height at which one of two safety criteria are exceeded; those criteria are the Head Injury Criterion exceeding 1000, and the maximum acceleration due to the impact exceeding 200 g. The critical fall height is determined by dropping an instrumented headform from various heights onto the artificial grass surface and measuring the acceleration due to the impact. Heights tested include those which produce measurements that satisfy the relevant criterion and those which exceed the relevant criterion.
It should also be noted that the impact results reported here relate specifically to the installation of the product as specified by Artgrass below and no allowance has been made for incorrect installation, ageing or degradation of the product. These results should always be used in consultation with the installation authority.
The critical fall height has been calculated relative to a nominated piece of equipment and no assumption has been made about the height of the user above that equipment. The critical fall height is quoted to the nearest 0.1 m, rounded down, as specified in AS/NZS 4422:1996.
The Product Tested for the Impact Results
The artificial grass tested was supplied by Artgrass, of Hurstbridge, VIC and is described as “EVA Impact Surface Tile (40mm) under Sand-filled Artificial Grass with a pile height of (40mm)”. The product sample consisted of an EVA foam tile surfacing covered with artificial grass, with an approximate average measured thickness of 80mm. The test sample consisted of two layers of interlocking EVA bonded together by the manufacturer, underneath a layer of 40mm sand filled artificial grass, resulting with a final test piece of approximately 1m×1m in dimension. The testing was conducted at the Thebarton Campus of the University of Adelaide.
The Installation and substrate
The product sample consisted of a single combined test piece (of dimension 1m2), resting flat against the substrate of a concrete floor.
The Testing of the Artificial Grass
This product was tested to the requirements for AS/NZS 4422:1996. The position of the test
locations on the product sample are shown in Figure A1. Results at locations A,B & C are presented in this report.
The Conditions on the day of Testing.
Time: 11:30am
Air Temperature: 21°C
Surface Temperature: 21°C
The Test Results:
The results for the “EVA Impact Surface Tile
(40mm) under Sand-filled Artificial Grass with pile height of(40mm)”
product are displayed in Table A1 below:
The Critical fall height
The calculated critical fall height for this artificial grass product is 1.6m, based on the HIC & Acceleration values measured at the height of 1.7m in the second and third drop tests in Table A1 above.
The Graphical results Figures A2 and A3 show how the HIC values and the peak accelerations vary with the minimum fall height. Figure A4 shows an actual acceleration trace from
the tests; specifically from the second drop test at a height of 1.7m.
The Multiple References
AS/NZS 4422:1996, Playground surfacing - Specifications, requirements and test method.
THE TEST CERTIFICATE TO ARTGRASS
This is to certify that the product sample: “EVA Impact Surface Tile (40mm)
under Sand-filled Artificial Grass (40mm)” safety surfacing, produced
by Artgrass (as described in MechTest Report: MT0976c), has been
assessed according to the impact test procedure described in Australian/New
Zealand Standard: AS/NZS 4422:1996.
Tests were conducted on the impact absorption properties of this EVA foam tile under
surfacing covered with artificial grass product, having an average combined total
thickness of 80 mm or eighty millimetres (measured on the day of testing). As a result, the following
specification was determined:
Product: “EVA Impact Surface Tile (40mm) under Sand-filled Artificial
Grass with pile height of (40mm)”
Test Date: 1st December 2008
Critical fall height: 1.6m.
This page does represent a summary of the major findings of the MechTest report: MT0976c. For more detailed information regarding any aspect of the test procedure, the interpretation of test results or the description details of the product tested, please refer to the MechTest Report: MT0976c (in its entirety).
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