Cleaner Technology Projects in Denmark 1997
Life-span of Buildings and Building Materials
Bygningers og byggematerialers levetid
Arbejdsrapport nr. 48, 1997, Miljøstyrelsen
This report describes the results of a pre-project titled "Life-span of Building Materials" (Byggematerialers levetid). The purpose of the pre-project was to plan and test methods of registration in order to make a more substantial registration of the life-span of various building materials and building components possible in the future.
The report has been divided into 9 sections:
Section 1 contains a description of three different methods of registration, as well as an account of the choice of methods used in the project.
Section 2 describes four different concepts of life span and defines the project in relation to these concepts.
Section 3 states information about: Use of materials, types of buildings together with the various environmental impacts of the building components in order to make it possible to prioritise the choice of building components and materials.
Section 4 gives an account of the system structure, choice of building components and registration criteria.
Section 5 explains the different areas where it might be possible to make use of the changes.
Section 6 describes a system test of a concrete building component.
Section 7 presents the treatment and the interpretation of the results from the test.
Section 8 gives a description of further tests on two other building components.
Section 9 discusses the method of registration and the results of the data processing.
In addition to this, the report contains a bibliography and a number of appendices, which have made it possible to effectuate the registration.
On the basis of registrations, it is possible to conclude that the statistical method is very useful: To collect knowledge about the life-span of building materials, how the life-span is effected by various environmental conditions depending on constructive presentation of the building, as well as the relative distribution of materials used for the current building component.
There are a number of pre-conditions that have to be made in order to evaluate the results:
 | A representative choice of materials |
| The symptoms, which are the base for the estimation of the life-span, must be described precisely and in objective terms |
| The number of registrated units must be comprehensive enough to make statistical calculations possible, within an acceptable uncertainty |
| A large spreading within the particular categories must be considered when the results are evaluated. |
| The method of registration should be explained by education and/ or the registrars should have a direct interest in the result of the registration. |
The uncertainties, which have been found during the test project, are in connection with the following:
| A material where it has not been possible to predict the long-term development, since it has only been on the market for a very short period. |
| Materials which only have been used on a inferior scale and therefore can be influated by the "law of the small numbers" (single results) |
| Materials which have had an remarkable change during the development process by undergoing a product development |
| Other materials have substituted materials, which according to experiences have a short life-span but to a wide extent. Because of this the remaining units have been subjected to exceptionally positive conditions |
| A number of well-preserved units of a high age can influence the statistical calculations of the life-span period. |
The general conclusions, which can be made from the test registration, are:
| The different characteristics of the materials will stand out quickly |
| The general knowledge about the life span of materials should be adjusted the use and the influence they are subjected to. |
Author/ institution
DTI Byggeri
Skafor
This report is subsidised by the National Council for Recycling and Cleaner Technology
ISSN no. 0908-9195
ISBN no. 87-7810-814-4