Why is the amount of UV exposure limited for Epoxy-Coated Steel Reinforcing Bars?
In Section 6 of ASTM D3963 “Standard Specification for Fabrication and Jobsite Handling of Epoxy-Coated Reinforcing Steel Bars” it is required that: “Placed coated bars shall be covered with opaque polyethylene or similar protective material if cumulative environmental exposure of the coated bars, including previously uncovered storage time, of greater than two months prior to concrete embedment is expected.” The provision for two-months of exposure was developed from testing conducted by C-SHRP where bars were left exposed and then tested. (See: http://www.cshrp.org/products/outdoor.pdf ) It is known that extended exposure is often unforeseen and that bars may be exposed for longer periods than that suggested by ASTM D3963. Fusion-bonded epoxy coatings may undergo surface discoloration and chalking from exposure. The Epoxy Interest Group of CRSI cannot endorse the use of products in non-specified manners; however, should extended exposures occur, it is strongly recommended that the ba
