EN 1606 Thermal Insulation Products for Building Applications - Determination of Compressive Creep

A European standard "EN 1606 Thermal insulation products for building applications - Determination of compressive creep" defines equipment and procedures for determining the compressive creep of samples under various stress conditions. This standard is also applicable to thermal insulation products.

For the purposes of this standard, the following terms and definitions apply:

• Thickness refers to the linear dimension measured perpendicular to the length and width plane.
• Compressive stress is the ratio of the compressive force to the initial surface area of ​​the sample cross-section.
• Deformation refers to the decrease in thickness of the sample.
• Relative deformation expresses the ratio between the deformation and thickness of the specimen and is measured in the loading direction.
• Compressive creep refers to the increase in deformation of a sample under a constant stress with time under specified temperature and humidity conditions.

In principle, compressive creep is determined by measuring the increase in deformation of a sample under constant compressive stress and specified conditions of temperature, humidity, and time.

The main equipment used in these tests includes:

• Loading device: Consists of two flat plates, one of which is movable and arranged to compress the specimen in the vertical direction. The movable plate is oriented to be self-aligning. The plates must be capable of being loaded uniformly and without distortion so that the static stress does not vary more than plus/minus 5 percent during the test.
• Measuring instrument (e.g. dial indicator): A device capable of determining the distance between two plates, i.e. the deformation of the sample, with an accuracy of 0,01 mm.
• Suitable damping measures: Necessary to minimise the effects of external vibration (e.g. the essential foundation of the device support). Examples of the test device are included as given in the standard.

Samples for determining compressive creep shall be taken from the same sample and with the same preparation as those used for the pressure test specified in EN 826. The method of selecting the samples shall be as specified in the relevant product standard. In the absence of a product standard or other technical specification, the method of selecting the test samples may be freely agreed upon between the parties.

The thickness of the samples shall be equal to the thickness of the original product. The width of the samples shall not be less than the thickness. Products with faces or integrally molded skins that have been retained in service shall be tested with these faces or skins intact. Test samples shall not be layered to produce greater thickness for testing. Samples shall be cut square and have edges with the following recommended dimensions:

• 50 mm x 50 mm
• 100 mm x 100 mm
• 150 mm x 150 mm
• 200 mm x 200 mm
• 300 mm x 300 mm

The dimensions of the specimens shall be the same as those used in the pressure test as described in standard EN 826. These shall be specified in the relevant product standard or agreed upon freely between the parties. The linear dimensions shall be determined in accordance with standard EN 0,5 with an accuracy of 12085 per cent. The tolerance for parallelism and flatness between the top and bottom faces of the specimen shall not be greater than 0,5 per cent of the edge length, a maximum of 0,5 mm. If the specimen is not flat, it shall be flattened or a sufficient coating shall be applied to prepare the surface for testing. If coated, the coating shall not show significant creep or shall be taken into account by deducting the creep of the coating.

The number of samples shall be as specified in the relevant product standard. If no number is specified, at least three samples shall be used for each selected compressive stress. In the absence of a product standard or other technical specification, the number of samples may be freely agreed upon between the parties.

Test specimens shall be cut in such a way that the direction of loading applied to the product corresponds to the direction of the compressive forces applied to the product during use. Specimens shall be cut by methods that do not alter the original structure of the product. For products with non-parallel faces, the parallelism of the top and bottom faces of the specimen shall be in accordance with this standard. Where necessary, specific preparation methods may be given in the relevant product standard.

Samples shall be conditioned for at least 24 hours under test conditions. In case of disagreement, the conditioning period (balance of moisture content) shall be as specified in the relevant product standard.

The test is carried out at a temperature of 23 degrees plus/minus 2 degrees and a relative humidity of 50 percent plus/minus 5 percent. Other conditions may be given in the relevant product standard or freely agreed upon between the parties.

The test is performed at three or more different stresses. Only this level is used to verify a defined stress level. Alternating stresses for creep testing shall be based on the compressive strength or compressive stress at 826 percent strain measured in accordance with EN 10 and calculated in accordance with the criteria given in the standard.

If the thickness of a specimen is to be determined without the use of a loading device, it shall be measured to an accuracy of 12085 mm in accordance with EN 0,1. The specimen is carefully placed in the loading device under the dead weight of the loading device. The thickness under this load shall be considered as the reference value for deformation measurements. The stress exerted by the dead weight shall be less than 10 percent of the minimum stress selected for the test.

Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "EN 1606 Thermal insulation products for building applications - Determination of compressive creep" standard are also provided to businesses.