Epoxy polymer overlay systems are designed to protect concrete structures and prolong the life of bridge decks and elevated concrete decks. Much of the wear and damage to these structures can be traced to corrosive de-icing chemicals that can migrate into the concrete and through cracks in the structure. Over time, if left unprotected, the concrete matrix can weaken and the reinforcing structures within the concrete may erode and shorten the life cycle of the concrete structure.
Until recently, E-Chem’s products – EPX50-Overlay Resin Polymer, EPX50-Overlay Fast Setting Formulation, and EP50-Overlay – were limited by their use only in conditions above 45 ˚F. Anything below 45 ˚F, and the molecules won't continue to crosslink to cure for an effective and protective bridge deck overlay system. As a result, these construction activities have been relegated to spring through fall construction periods.
Today, however, chemists from Meridian Adhesives Group, E-Chem's parent company, have developed a product called EPX50LT Overlay that will perform in conditions as low as 30 ˚F.
"A lot of times, the radical chemistry of polyester resin binders uses harsher chemicals or possibly some other volatiles that are more difficult to deal with and require more worker protection. You also get into flammability concerns and health concerns,” explained to Artem Bobylev, senior R&D chemist at Meridian. “Our system doesn't use polyether amines, a curing compound common for epoxy resins. Instead, it relies on primary amines and specific crosslink density for the final polymer to achieve better flexibility at lower temperatures and with a lower temperature cure.”
EPX50LT conforms to ASTM C881 as well as AASHTO (American Association of State Highway and Transportation Officials) M235 standards for DOT requirements that encompasses not just these overlays, but also the bonding agents and anchoring adhesives. EPX50LT lab and field testing shows that the material can be successfully used at lower temperatures with all the performance qualities it requires. It also shows that it can cure at lower temperatures and have a faster set time, so a quicker return to service is possible.
“California is one state that is really looking for a rapid return to service within an hour or two for HFST (High Friction Surface Treatments). This product will allow them to do that, plus deliver on the high friction surface treatment side of the business,” observed Bobylev.
EPX50LT is non-flammable and contains zero VOCs. It is 100% epoxy, bonds to most surfaces, and provides a more durable binder than polyester-styrene resin. Contractors prefer the installation of epoxy polymer resins over polyester polymer resins due to the ease of placement, workability, mixing, and lower PPE requirements.
Learn more about EPX50LT and all the epoxy polymer bridge preservation products from Meridian’s E-Chem brand at https://e-chem.net/overlays/.
