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BUILDING COMPONENTS AND MATERIALS

Weathering Factors

Radiation

Solar

Nuclear

Thermal

Temperature

Elevated

Depressed

Cycles

Water

Solid (such as snow, ice)

Liquid (such as rain, condensation, standing water)

Vapor (such as high relative humidity)

Normal Air Constituents

Oxygen and ozone

Carbon dioxide

Air Contaminants

Gases (such as oxides of nitrogen and sulfur)

Mists (such as aerosols, salt, acids, and alkalies dissolved in water) Particulates (such as sand, dust, dirt)

Freeze-thaw

Wind

Biological Factors

Microorganisms

Fungi

Bacteria

Stress Factors

Stress, sustained
Stress, periodic

Stress, random

Physical action of water, as rain, hail, sleet, and snow

Physical action of wind

Combination of physical action of water and wind

Movement due to other factors, such as settlement or vehicles Incompatibility Factors

Chemical

Physical

Use Factors

Design of system

Installation and maintenance procedures

Normal wear and tear

Abuse by the user

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Let A represent either the exterior-most or interior-most element

Let A-B, B-C, etc. represent interfaces between elements

Figure 2. Example of a Matrix for Identifying Observable Changes of Building Components and Materials

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An Approach to Improved Durability Tests for Building
Materials and Components

7. AUTHOR(S)

Geoffrey Frohnsdorff. Larry W. Masters. Jonathan W. Martin 9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS
DEPARTMENT OF COMMERCE
WASHINGTON, DC 20234

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State, ZIP)

Same as 9 above

3. Recipient's Accession No.

5. Publication Date

July 1980

ing Organization Code

8. Performing Organ. Report No.

10. Project/Task/Work Unit No.

11. Contract/Grant No.

13. Type of Report & Period Covered Final

Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant bibliography or literature survey, mention it here.)

Durability tests usually provide relative measures of the time building materials and components will perform their intended functions under the expected service conditions. This is not adequate to ensure the proper selection of new building materials and components because quantitative measures of long-term performance are needed. Although many tests have been developed to accelerate degradation processes of building materials, they are seldom fully adequate for reliably predicting long-term performance. In this paper, a recommended practice, ASTM E 632-78, which provides a framework for the development of improved durability tests, is outlined. The application of the recommended practice, which does not specify an analysis procedure, is illustrated by examples from the literature using both deterministic and probabilistic approaches.

While probabilistic concepts have not been applied extensively to materials durability problems in the construction industry, these concepts offer new opportunities for obtaining improved quantitative predictions of the service life of building materials.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons)

Accelerated aging tests; building components; building materials; durability; life testing; prediction; recommended practice; reliability service life.

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