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Physical Properties of GRC |
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Physical Properties of GRC
| Thermal |
| Property |
Unit of Test |
Performance |
| Expansion |
Per ºK |
10 - 20 x 10 |
| Conductivity |
W/M ºK |
0.5 - 1.0 |
| Freeze thaw |
BS 4264 |
no visible or mechanical change |
| Din 278 |
no visible or mechanical change |
| ASTM C666.73 |
after 300 cycle + 20º C relatively little change |
| Fire |
| Property |
Unit of Test |
Performance |
| Non Combustiblity |
BS 476 PI 4 |
Non combustible |
| Ignitability |
BS 476 PI 5 |
Class P ( Not easily ignitable ) |
| Fire propagation |
BS 476 PI 6 |
Class O |
| Spread of flame |
BS 476 PI 7 |
Class 1 ( Zero spread) |
| Fire resistance |
BS 476 PI 8 |
0 - 4 hours depending on construction |
| Smoke |
ASTM SIP 4422-67 |
Dm=2-6 negligible smoke production |
| Moisture |
| Property |
Unit of Test |
Performance |
| Water vapour |
|
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| Permeability |
BS 3177 |
Permeance less than 1.3 metric perms at 10 mm thick |
| Water permeance |
BS 473/550 |
0.02 - 0.4 ml/m2 min on 8 mm thick |
| Moisture absorbtion |
|
10 - 20 % from oven dry to saturation |
| Moisture movement |
|
0.15 - 0.2 % from satration to oven dry |
| Accoustic Sound Absorpsion dB |
| Performance |
| 8 mm sheet 23 dB at 125 Hz |
| 40 dB at 4000 Hz |
| Abrasion Resistance |
| Unit of Test |
Performance |
| ASTM C418-68 |
0.27 - 0.30 cm3 volume loss. Lower loss than normal concrete, A/C sheet or brick. |
| Safety |
| Property |
Unit of Test |
Performance |
| Fibres in air |
Micron |
The
fibre diameter is greater than 12 microns and is therefore well above
the upper limit of respirability (3.5 microns diameter ). Detailed
medical information is available on request |
| Fibre |
WHO Standards |
GRC
can be used for system carrying potabel water. The fibres are firmly
bonded into the composite and not therefore realesed into the water.
GRC containing fibre produced no tatste color and turbidity where
uneffeced at level exceeding specification. |
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GRC Product