The authors developed a new aseismatic reinforcing method for existing RC columns in order for easy and quick maintenance work in daily and emergency inspections after earthquakes. In this new method, manufactured spiral tendons bind precast concrete blocks around the columns. In order to confirm the aseismatic performance of the new method, we conducted cyclic loading tests using 5/8 scale model columns. These tests demonstrated that the new method have more ductility and enable easier visual inspections than the conventional methods and is an effective aseismatic reinforcing method for the existing RC columns of rigid-frame railway viaducts.