- Author
- Sleater, G. A.
- Title
- Stone Preservatives: Methods of Laboratory Testing and Preliminary Performance Criteria. Final Report.
- Coporate
- National Bureau of Standards, Washington, DC
- Sponsor
- National Park Service, Washington, DC
- Report
- NBS TN 941, May 1977,
- Distribution
- Available from National Technical Information Service
- Keywords
- construction materials; rocks; preservatives; accelerated tests; environmental tests; weathering; thermal properties; chemical attack; buildings; performance evaluation; ultraviolet radiation; sulfuric acid; corrosion tests; sodium sulfates; sodium chloride; specifications; criteria; air pollution
- Identifiers
- air pollution effects (materials)
- Abstract
- Although numerous materials have been proposed as preservatives for stone in historic buildings and monuments, their efficacy is difficult to establish. A laboratory research program of accelerated simulated stone decay was used to obtain data on stone preservatives and to suggest criteria for their selection. Over 50 materials usable as stone preservatives were tested. Tests to simulate stone decay were of two types: (1) Exposure to combined weathering factors using a special test chamber for accelerated decay (CAD), in which chemical attack, salt and water action, and thermal effects were simulated in one operation; (2) Exposure to single causes of stone decay using sulfurous acid fog, sodium chloride fog, water condensation/evaporation cycling, sodium sulfate penetration and crystallization, and ultraviolet radiation. Methods for measuring the effects of the exposures are given together with the test data; these have been used to set limits of acceptable performance in preliminary performance criteria for the selection of stone preservatives. The behavior of each stone preservative tested in meeting these criteria is given. No one stone preservative met all criteria.