Performance of Two Thin Epoxy Overlays on New Concrete Under Laboratory and Outdoor Exposure Conditions

Thin epoxy overlays are used for improving condition and extending service life of bridge decks. The tensile bond pull-off strength, evaluated as per the ASTM C1583, is used as the performance indicator. A failure in substrate with a tensile strength of 250 psi or greater is considered acceptable. However, the performance evaluated on in-service bridge decks shows inconsistent results. Such studies failed to record and correlate the parameters that influence overlay performance during testing to clarify the observed variations. Laboratory studies by several researchers documented distinct performance between room and elevated temperature conditions. However, the most influential parameters such as substrate moisture variation against temperature were not measured and correlated to the observed performance. This study was initiated to provide clarifications to the observed performance differences by evaluating the impact of epoxy properties (e.g., viscosity), concrete age at the time of epoxy application and performance evaluation, concrete mix ingredients, exposure conditions, concrete microstructure development, and substrate moisture and temperature. Experimental results indicated that (i) epoxy overlays showed better performance in concrete mix with slag, (ii) the low viscous epoxy overlay showed better performance than high viscous epoxy overlay, irrespective of evaluation parameters, and (iii) substrate moisture vapor pressure developed under elevated temperature negatively affects the overlay performance. Results also indicate the need for developing specifications to evaluate overlay performance and thermal compatibility between epoxy and concrete under elevated temperature.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: 20p

Subject/Index Terms

Filing Info

  • Accession Number: 01763437
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-03906
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 10:59AM