PERFORMANCE SPECIFICATION
GLASS REINFORCED GYPSUM (GRG)
1.0.1 PHYSICAL CHARACTERISTICS
1.1.1 Water Penetration
The material shall be suitable for all internal application, and shall not absorb moisture which may be present through excessive humidity.
1.1.2 Fire Propagation
The material so tested shall be designed P (i.e. to achieve Class 0) and have a final fire propagation index of 0.9 with intermediate indices.
i. 0.69 ii. 0.06 iii. 0.12
The material so tested shall produce no smoke.
Surface Spread of Flame - the material shall be tested in accordance with BS476 Part 7 1971 and shall be classified Class 0.
Non-Combustibility - the material shall be tested in accordance with BS476 Part 8 1970 and shall be classified NON COMBUSTIBLE
1.1.3 Chemical Resistance
The material shall have a thermal conductivity (k) value of not greater than 0.375 W/M deg. C.
1.1.5 Density
The material shall have a density not exceeding 1500kg/m².
1.1.6 Expansion
The material shall have a thermal coefficient of expansion not exceeding 14.94 x 10-mm/degC.
1.1.7 Structural Characteristics
The material shall have an ultimate tensile strength of not less than 8.27/mm².
The material shall have an impact strength of between 16812-17232N/mm²
The material shall have a Rockwell hardness classification of M72.
1.1.8 Anti Static
The material shall hold negligible static charges in order to minimise dust attraction.
1.1.9 Ultra Violet
The material shall not be affected by ultra-violet light.
1.1.10 Asbestos
The material shall contain no asbestos.
1.1.11 Fungoid Attack
The material shall not sustain fungoid growth under normal conditions.
1.0.2 Plaster
High quality hard casting plaster with expansion coefficient. Polymers can be added to increase the density, hardness, and resilience.
1.0.3 Glass Fibre Mat
The reinforcement of the plaster is Glass Fibre Matt.
1.0.4 Metal Rod
At fixing locations metal rods on flat beds are encased in the plaster.
1.0.5 Water
Clean water fit for drinking and used in such proportion as to ensure maximum workability and optimum water/plaster ratio.
1.0.6 Mould Release Agents
Proprietary mould release agents/waxes applied to the moulds between each production. The agents/waxes shall not have any adverse effect upon the surface of the component.
2.0.0 Workmanship
2.0.1 Design Mix
All components shall be manufactured to a consistent mix, with all constituent materials accurately gauged, batched, or weighed.
2.0.2 Curing
All components shall be cured for 12 hours in a dehumidifying oven at a constant thermostatically controlled temperature of 30ºc and moisture extraction rate to maintain a relative humidity of 30%.
2.0.3 Quality Control
All components shall be individually inspected and any surface blemishes rectified accordingly.
2.0.4 Performance
Each component shall within the following limits, be true in shape and free from cup and bow.
2.4.1 Squareness
The component where rectangular shall be tested for squareness by measuring the diagonals. The difference between the two measurements shall not exceed 0.5% of the length of the diagonal.
2.4.2 Flatness
The deviation from the horizontal plane shall not exceed +1mm in 1m length.
2.4.3 Dimensional Tolerance
The dimensional accuracy of any component shall be within +2mm in 1m length.
3.0.0 Joints in Glass Reinforced Gypsum
Joints in Glass Reinforced Gypsum will be established prior to manufacture to provide tolerances and position to suit the design of the feature. All panels to be aligned perfectly to ensure a continuous straight line for items in excess of manufactured lengths, materials used to fill joints are to comply with manufacturers recommendations and be compatible with the adjoining interfaces.