Research on prevention of collapse of existing dangerous masonry walls by reinforcement using polyurea resin and aramid fiber tape

In June 2018, an earthquake of intensity of less than 6 occurred in Osaka. At that time, there was a case that the girl was underlaid by the collapse of the concrete block wall, and she died. Also, in the Netherlands, earthquakes occur frequently due to the influence of gas sampling in recent years. There are many masonry using bricks, but such a masonry is very vulnerable to earthquakes. In recent years, major earthquakes have occurred not only in the Netherlands, but also around the world. Masonry buildings around the world are at risk of earthquakes. This research aims to discover excellent reinforcement methods for preventing collapse against earthquakes of these masonry using concrete blocks and bricks. We focused on polyurea resin and aramid fiber. In this research, we prepared masonry walls made of Japanese concrete blocks and masonry walls made of bricks as a target of reinforcement. Reinforced specimens by polyurea resin sprayed to a thickness of 5 mm over the entire surface, by blue thin aramid fiber tape attached, by black thick aramid fiber tape attached, or by both tapes attached were prepared. Test specimens were laid down sideways, the center part was pushed with an Amsler Testing Machine, and a bending test was carried out until the center part was deformed to 40 mm. Specimens are required to have seismic performance that can withstand a horizontal load of (self-weight) x (1G). As a result, it was found that all reinforced specimens had seismic performance exceeding that required. Moreover, the effect of these reinforcements was confirmed from several points in this experiment.