<p>In the case of repair and reinforcement of an R/C structural frame, and installation of new members for extension and reconstruction, it is necessary to anchor main bars and wall reinforcement bars of new members to the existing frame.</p><p>In this case, the anchor is required to reliably transfer the tension of the rebar to the existing frame. The purpose of this research is to propose a post-installed headed rebar anchor method with high reliability both in structural performance and workability, and to evaluate the anchorage performance of the method.</p><p>In the third part of the authors’ research, a shear experiment was conducted to clarify the structural performance of the post-installed rebar anchor with small headed plate under the combined load of tension and shear. In the test, shear force was applied to a joint surface where the rebars were anchored with the proposed method. The number of test specimens was 10, and the parameters of the test were anchoring method, concrete strength, tensile load level, and edge size (rebar spacing).</p><p>The following results were obtained.</p><p>(1) The shear resistance of the post-installed rebar anchor of the proposed method is similar to that of the cast-in-place rebar even when its diameter is large or concrete strength are different, and the shear resistance is dominated by the dowel action.</p><p>(2) The allowable shear load (stress) can be evaluated by applying the steel structure bolt method for the fracture of rebar and the bearing strength of concrete for the failure of anchor area. The displacement can be controlled to 1 mm or less at the long-term allowable load and about 5 mm or less at the short-term allowable load even when the tensile force is applied.</p><p>(3) At the maximum load, the increase of load is small due to the effect of cyclic loadings, but the ductility is large due to the yielding of the rebar. The ultimate shear capacity can be evaluated by the existing evaluation method considering the reduction due to cyclic loading.</p><p>(4) The shear force-displacement relationship can be evaluated using the existing evaluation method for the dowel action of the PCa connection by modifying its horizontal reaction coefficient of concrete when tensile force is applied.</p>