An anchor bolt assembly having a generally cylindrical grip end spaced from an actuating end. The grip end has two relatively movable mating portions each having at least one complementary ramp surface. The actuating end is used to move a movable mating portion relative to a fixed mating portion in a longitudinal direction. Actuation will cause the movable mating portion to slide relative to the static mating portion and apply radial pressure at the grip end of the anchor bolt assembly remote from the actuating end. The grip end has a roughened surface on the static mating portion while the movable mating portion is smooth. The anchor bolt assembly is particularly suitable for use in tapered holes formed in concrete.