PURPOSE: To obtain the subject binder for fixing an anchor bolt to a concrete, a rock wall, etc., having an improved initial adhesion and an improved alkaline resistance by blending a resin composition having a specified composition, a crosslinkable monomer and a curing agent.

CONSTITUTION: An objective binder containing (A) a resin component obtained by blending 100 pts.wt. unsaturated polyester resin (preferably 2000-3500 molecular weight) containing a bisphenol A-alkylene oxide adduct as its polyvalent alcohol component with 5-80 pts.wt., preferably 20-80 pts.wt. epoxyacrylate resin (preferably 500-800 molecular weight), (B) a crosslinkable monomer (e.g. styrene or vinyl acetate) and (C) a curing agent (e.g. methyl ethyl ketone peroxide).