Category:1136 Modified Urethane or Polyurethane Elastomeric Coating
|Current General Services Specifications (MGS) By Subject|
Laboratory Testing Guidelines
This article establishes procedures for Laboratory testing and reporting of modified urethane or polyurethane elastomeric coating for concrete bents and piers.
To obtain qualification, the manufacturer shall submit one unit of each component, pre-packaged to exact mixing quantities for one gallon (4 liters), to:
- State Construction and Materials Engineer
- Missouri Department of Transportation
- P.O. Box 270
- Jefferson City, Missouri 65102
The sample shall be clearly identified as to brand name, manufacturer's name and address and accompanied with the following information:
- a) Manufacturer's complete material data showing test results for the properties specified, generic name of the major components of the material, mixing instructions, any modification to the standard tests herein specified and intended use.
- b) Test results after 1000 hours exposure in a Fluorescent & UV-Condensation Weathering apparatus (QUV), in accordance with ASTM G53, Procedure B. Test specimen film thickness shall be 40 mils and shall show no cracking, flaking or blistering after exposure. Slight discoloration will be allowed.
- c) In lieu of the QUV test results required in the above paragraph b, the manufacturer may submit a use history showing satisfactory performance for 3 years in at least two exposed applications. Name, address and telephone number of the users shall be included in the use history.
Prequalification Sample Tests
Laboratory tests will be performed on the prequalification sample as follows:
- a) Percent Solids on the mixed material by weight, ASTM D1644 Method A. Method A may be modified at the manufacturer's option by air drying at 24° ± 1 °C for the length of time recommended by the manufacturer rather than by oven drying.
- b) Pot Life at 24° ± 1°C - Time, after which membrane cannot applied satisfactorily.
- c) The material shall not run or sag excessively when 40 mil film is applied to a vertical concrete surface.
- d) Shore A hardness after 7 day cure at 24° ± 1°C, 50% RH.
Upon completion of Laboratory tests and a review of manufacturer's data, the supplier will be notified by letter whether the material is qualified for use. Each qualified brand and the manufacturer's name and address shall be added to Qualified Modified Urethane or Polyurethane Elastomeric Coatings.
Random samples of material offered for use shall be tested in the Laboratory according to methods set forth in steps a through d of Prequalification Sample Tests, above, as a check on the manufacturer's test results.
The manufacturer's certification received with the sample is to be checked for compliance.
Original test data and calculations shall be recorded in laboratory workbooks. Test results shall then be recorded through SiteManager.
The sample record shall be completed in SiteManager, as described in Sample Record General Information , and shall indicate acceptance, qualified acceptance or rejection. Appropriate remarks, as described in EPG 106.20 Reporting, are to be included in the remarks to clarify conditions of acceptance or rejection. Test results on random samples shall be reported on the appropriate templates under the Tests tab.