NOVELTY - Blend comprises one or more epoxy resins, and a mixture comprising a hardening component (a) in an amount of 0.3-0.9 amine equivalent per epoxy equivalent of the used epoxy resin, and the component (b), where the component (a) comprises one or more amines with a functionality of greater than or equal to 2; at least one amine in stoichiometric mixture with the epoxy resin in 100 g of substance for hardening at room temperature for less than 24 hours; and the component (b) comprises at least one substituted guanidine compound (I).    USE - The blend is useful for producing hardened epoxy resins, which are useful as molded bodies such as reinforced body parts for rotor blades of wind turbines (all claimed), and fiber-reinforced plastics, which are useful as materials for automobiles, airplanes, ships and boats and sporting goods.    ADVANTAGE - The blend allows increased hardening rate of epoxy resin and/or the epoxy resin system without simultaneously increasing the viscosity of the epoxy resin mixture.    DETAILED DESCRIPTION - Blend comprises one or more epoxy resins, and a mixture comprising a hardening component (a) in an amount of 0.3-0.9 amine equivalent per epoxy equivalent of the used epoxy resin, and the component (b), where the component (a) comprises one or more amines with a functionality of greater than or equal to 2; at least one amine in a stoichiometric mixture with the epoxy resin in 100 g of substance for hardening at room temperature for less than 24 hours; and the component (b) comprises at least one substituted guanidine compound of formula (R1-N(R2)-C(=NH)-N(R3)-R4) (I).    R1-R3, R5, R6 = H or 1-20C organic residue; and    R4 = 1-20C organic residue or -C(NH)NR5R6-.    INDEPENDENT CLAIMS are included for:    (1) a process for producing the blend, comprising mixing one or more epoxy resins with the mixture at a temperature below the hardening temperature of the hardener component (a);    (2) use of the blend for the production of hardened epoxy resin;    (3) hardened epoxy resins obtained by the hardening of the blends; and    (4) molded bodies, obtained by curing a mold with a fiber-reinforced materials, and introducing the blend with an infusion technology into the mold.