Most of the Reinforced Concrete (RC) buildings constructed in the second part of the last century were generally designed by neglecting the interaction between the RC frame and the masonry infill walls. On the contrary, even in case of lateral loads caused by moderate seismic events, infills generally lead to an important increment of RC frames stiffness by acting as diagonal struts. Therefore, by considering the low dissipative capacity of the frames (without seismic detailing), infills becomes real structural elements that might govern the failure mechanism of the whole building. In view of this, a possible way for strengthening low rising RC buildings placed in low seismicity areas may be based on techniques aiming at improving the capacity of the masonry infills and exploiting the “box behavior” of the building. The present research aims at proposing the use of thin AR-glass fiber mesh reinforced mortar overlays for strengthening the infills located along the perimeter walls of the RC buildings. The main purpose of the retrofitting method is to achieve an improved capacity and ductility of the entire building by exploiting the effect of the strengthening layers applied on the external side of the perimeter walls. In order to assess the effectiveness of the proposed technique, a series of quasi-static cyclic tests on full scale infills made of hollow clay units with horizontal cores were carried out. A special RC frame provided with steel hinges connected at the columns edges was built to simulate the behavior of the frame when the ultimate mechanism is fully activated. A total of three specimens including a not strengthened wall as well as a strengthened and a repaired panel were tested. The latter proved that, compared to the unstrengthened panel, the reinforced mortar coating was able to improve the stiffness as well as the capacity of the masonry infills.
In-plane cyclic tests on hollow clay brick masonry infills retrofitted by glass fiber mesh reinforced mortar coating
FACCONI, Luca;MINELLI, Fausto;GIURIANI, Ezio Pilar
2016-01-01
Abstract
Most of the Reinforced Concrete (RC) buildings constructed in the second part of the last century were generally designed by neglecting the interaction between the RC frame and the masonry infill walls. On the contrary, even in case of lateral loads caused by moderate seismic events, infills generally lead to an important increment of RC frames stiffness by acting as diagonal struts. Therefore, by considering the low dissipative capacity of the frames (without seismic detailing), infills becomes real structural elements that might govern the failure mechanism of the whole building. In view of this, a possible way for strengthening low rising RC buildings placed in low seismicity areas may be based on techniques aiming at improving the capacity of the masonry infills and exploiting the “box behavior” of the building. The present research aims at proposing the use of thin AR-glass fiber mesh reinforced mortar overlays for strengthening the infills located along the perimeter walls of the RC buildings. The main purpose of the retrofitting method is to achieve an improved capacity and ductility of the entire building by exploiting the effect of the strengthening layers applied on the external side of the perimeter walls. In order to assess the effectiveness of the proposed technique, a series of quasi-static cyclic tests on full scale infills made of hollow clay units with horizontal cores were carried out. A special RC frame provided with steel hinges connected at the columns edges was built to simulate the behavior of the frame when the ultimate mechanism is fully activated. A total of three specimens including a not strengthened wall as well as a strengthened and a repaired panel were tested. The latter proved that, compared to the unstrengthened panel, the reinforced mortar coating was able to improve the stiffness as well as the capacity of the masonry infills.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
