Expandable, thermally curable compositions containing at least one epoxy resin, at least one polyester, at least one blowing agent, and at least one curing agent are useful as adhesives and structural reinforcement materials. When foamed and adhered to a metal substrate surface, such polyester-modified foamable compositions can exhibit improved adhesion to the substrate surface after exposure to a corrosive environment, as compared to compositions that do not contain polyester. Furthermore, these compositions can exhibit improved flow properties in the uncured state at temperatures between 50 and 100° C. They are granulatable, with the granules produced thereby having non-tacky surfaces at room temperature and being capable of being readily processed into molded objects by injection molding processes.