- Author
-
Wetterlund, I.
- Title
- Thermal Stability of Insulating Materials at High Temperatures. A Proposal for a New Nordtest Method.
- Coporate
- Swedish National Testing Institute, Boras, Sweden
- Report
-
SP REPORT 1994:66; Nordtest Project 1114-93
1994
23 p.
- Keywords
-
insulating materials
|
thermal stability
|
high temperature
|
building materials
|
fire tests
|
temperature distribution
|
test methods
- Identifiers
- temperature distribution in the specimen during test; how to measure the change in height
- Abstract
- A test method has been developed for determining the thermal stability of insulating materials at high temperatures. The test method based on SP Brand 207, is mainly intended for insulating materials for chimneys but can also be used for other purposes were the thermal stability at elevated temperatures is an important property. The principle of the test is that a specimen in a tube furnace is exposed to a temperature slowly increasing to 1100 ºC. The height shrinkage of the specimen is recorded. A product is defined as thermally stable if it does not shrink more than 50% of its initial height before the temperature has reached 1000 ºC. In the draft Nordtest method enclosed, the following was taken into account. The heating rate of the specimen must be selected low enough to facilitate accurate measurements. The suggested heating rate of 5 ºC per minute was verified by calculating the temperature distribution in the specimen during test with the computer code TASEF. With this heating rate, the difference between the furnace temperature and the mean temperature of the specimen will be less than 1 ºC. A thermocouple with a fast response is used for measuring the furnace temperature rise as accurate as possible. The height of the test specimen can be measured in different ways. Three methods are discussed. A video measuring system was more thoroughly investigated and found useful. With the selected heating rate the error contribution to the recording of the furnace temperature will be less than 1 ºC.