Epoxy overlays are applied on bridge decks after curing concrete in patches and repairs for 28 days. A tensile bond pull-off strength of at least 250 pounds per square inch (psi) is expected from a properly applied overlay. Even though the overlay performance at room temperature is mostly satisfactory, the performance at elevated temperatures is not convincing. The degradation of mechanical and adhesion properties of epoxy, shear stress at the concrete/overlay interface caused by thermal incompatibility, and the interface moisture vapor pressure are the commonly cited parameters for poor bond strength at elevated temperatures. A combined effect of these parameters results in the most unfavorable failure mode (which is bond failure at the concrete/overlay interface) at a strength lower than the specified limit of 250 psi. The moisture migration through concrete depends on many factors including moisture content along the depth of concrete, pore microstructure, exposure condition, and drying period. This study investigated the impact of concrete mix ingredients and surface treatments on the thin epoxy overlay bond strength. The results show that the use of concrete mixes with slag and penetrating sealant pretreatment improves the bond strength.

在修补和修复混凝土 28 天后，将环氧树脂覆盖层应用于桥面。从正确应用的覆盖层中，预计至少 250 磅/平方英寸 (psi) 的拉伸粘合拉脱强度。尽管室温下的覆盖性能大多令人满意，但高温下的性能并不令人信服。环氧树脂的机械和粘合性能退化、由于热不相容性引起的混凝土/覆盖层界面处的剪切应力以及界面湿气压力是高温下粘合强度差的常用参数。这些参数的综合影响导致强度低于指定限值 250 psi 时最不利的破坏模式（即混凝土/覆盖层界面处的粘结破坏）。通过混凝土的水分迁移取决于许多因素，包括沿混凝土深度的水分含量、孔隙微观结构、暴露条件和干燥时间。本研究调查了混凝土混合料成分和表面处理对薄环氧树脂覆盖层粘合强度的影响。结果表明，使用掺有矿渣和渗透密封剂预处理的混凝土可提高粘结强度。