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, 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 WATER ABSORPTION REFLECTANCE ABRASION RESISTANCE TRANSPARENCY TEXTURE SURFACE WETTABILITY 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 An Approach to Improved Durability Tests for Building 7. AUTHOR(S) Geoffrey Frohnsdorff, Larry W. Masters. Jonathan W. Martin 9. PERFORMING ORGANIZATION NAME AND ADDRESS NATIONAL BUREAU OF STANDARDS 12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State, ZIP) Same as 9 above 7. Recipient's Accession No. 5. Publication Date July 1980 g Organization Code 8. Performing Organ. Report No. 10. Project/Task/Work Unit No. 11. Contract/Grant No. 13. Type of Report & Period Covered Final 1. 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. |