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ETV Program Report: Coatings for Wastewater Collection Systems - Epoxy Tec International, Inc., CPP RC3
Citation:
CIGMAT. ETV Program Report: Coatings for Wastewater Collection Systems - Epoxy Tec International, Inc., CPP RC3. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/136, 2010.
Impact/Purpose:
To inform the public.
Description:
The Epoxytec, Inc. CPP™ epoxy coating used for wastewater collection system rehabilitation was evaluated by EPA’s Environmental Technology Verification Program under laboratory conditions at the Center for Innovative Grouting Material and Technology (CIGMAT) Laboratory at the University of Houston. Testing was conducted over a period of six months to evaluate the coating’s (1) chemical resistance and (2) bonding strength for infrastructure applications. For chemical resistance, coated concrete and clay bricks with holidays (holes created in the coating) were used to evaluate the chemical resistance of the coating/substrate bond under a corrosive environment. Twenty coated concrete (dry and wet) and 20 coated clay brick (dry and wet) specimens were exposed to DI water and sulfuric acid solution (pH=1), and the specimens were visually inspected and weight changes measured. Evaluation of the coating-to-substrate bonding strength was determined using two modified ASTM test methods – one to determine bond strength of the coating with two specimens sandwiched together using the coating, and the second to determine the bond strength by applying a tensile load to the coating applied to specimens of each substrate. Forty-eight bonding tests were performed over the six month evaluation. The tests resulted in the following conclusions about Epoxytec CPP™ : • After the six-month chemical exposure tests, all dry- and wet-coated concrete and clay brick specimens, with and without holidays, showed no major change in appearance with only some discoloration of the coating material noted; • For all 48 bonding tests, the observed failures were: substrate (60%), bonding/substrate (6%), bonding (17%) and bonding/coating (17%) failures; • Average tensile bonding strength for dry-coated concrete varied from 153 to 280 psi, with concrete substrate (92%) and bonding/substrate (8%) failures; • Average tensile bonding strength for wet-coated concrete varied from 92 to 236 psi, with bonding failures (67%) and bonding/coating failures (33%); • Average tensile bonding strength for dry-coated clay brick varied from 190 to 364 psi, with clay brick substrate failures (83%) and bonding/coating failures (17%); • Average tensile bonding strength for wet-coated clay brick varied from 184 to 342 psi, with clay brick substrate failures (67%), bonding/substrate failures (17%) and bonding/coating failures (17%).
URLs/Downloads:
ETV PROGRAM REPORT: COATINGS FOR WASTEWATER COLLECTION SYSTEMS - EPOXY TEC INTERNATIONAL, IN., CPP RC3VERIFICATION STATEMENT