Smart Strengthening of Existing RC Piers with SD490 and PCM

A smart seismic strengthening method of existing RC piers is being developed. In this method, longitudinal high strength re-bars (SD490) for strengthening are touched an existing column surface and mounted to base concrete, and special polymer cement mortar (PCM) is sprayed directly over the re-bars by a dry spray system. This method has two special features; one is that anchored longitudinal re-bars have a T-nut at the anchored end for decreasing the anchor length, and the other is that the direction of coring for anchoring re-bars is slanted for touching anchored re-bars to a surface of an existing column. A reversed cyclic loading test and an analysis were carried out to investigate the effect of the seismic strengthening by this method. From the results, it is cleared that the verification of the seismic performances of the bridge pier strengthened with SD490 and the polymer cement mortar may be carried out according to Specifications for Highway Bridges.