Category:1136 Modified Urethane or Polyurethane Elastomeric Coating

This article establishes procedures for inspecting, acceptance and reporting modified urethane or polyurethane elastomeric coatings to be used for sealing the caps and seats of concrete bridge piers, bents and abutments as specified in the Bridge Special Provision – Protective Coating for Concrete Bents and Piers (Deleterious Agents).

1136.1 Apparatus

Sample containers shall be one-quart (1 liter) screw top cans that are clean, dry and free of all contaminants.

1136.2 Procedure

1136.2.1 List of Qualified Materials

A list of brand names and manufacturers of modified urethane or polyurethane elastomeric coatings qualified in accordance with the specifications is available.

1136.2.2 Basis of Acceptance

Qualified materials will be accepted for use on the basis of a satisfactory manufacturer's certification plus sampling and testing.

1136.2.3 Certification

The manufacturer shall furnish a certification stating that the material furnished conforms to all requirements specified and that the material is of the same composition as that submitted for prequalification.

1136.2.4 Sampling

Samples are to be taken from each batch or lot furnished. The sample size shall be one unit of each component. The sample should be recorded in SiteManager, including complete information as to brand name, lot or batch number, and project or purchase order number and sent to the Central Laboratory. In addition, a copy of the manufacturer's certification for the lot or batch sampled shall be forwarded with the sample. See 106.5.2.2 Transportation of Samples and 106.5.3 Sampling Supplies for packaging, labeling and marking instructions.

1136.3 Sample Record

When samples are submitted to the Laboratory, the Laboratory will complete the test reports. If the material is accepted in the field, it shall also be reported through SiteManager and shall show all pertinent information. A copy of the certification shall be attached to the sample and a copy retained in the district files. The record is to indicate acceptance, qualified acceptance, or rejection. Appropriate remarks, as described in The Rounding Off Method, are to be included in the report to clarify conditions of acceptance or rejection.

1136.4 Laboratory Testing Guidelines

This article establishes procedures for Laboratory testing and reporting of modified urethane or polyurethane elastomeric coating for concrete bents and piers.

1136.4.1 Procedure

1136.4.1.1 Qualification Testing

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 Project Operations Engineer-Materials

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.

1136.4.1.2 Acceptance Testing

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.

1136.4.2 Sample Record

The sample record shall be completed in SiteManager, as described in Automation Sec 3510, and shall indicate acceptance, qualified acceptance or rejection. Appropriate remarks, as described in 106.9 Reporting Test Results, 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.