Strengthening Effect of the Fixing Method of Polypropylene Band on Unreinforced Brick Masonry in Flexural, Shear, and Torsion Behaviors

Abstract

Every year, Vietnam faces typhoons accompanied by strong winds. Semi-permanent houses are severely damaged by these winds. We researched a strengthening method using a Polypropylen (PP) band to prevent housing damage caused by strong winds. In this study, we have developed a new method of fixing PP band to bricks. The PP band is sandwiched between two flat steel washers and fastened with steel screws to a plastic plug embedded in the side of the brick. A total of 49 specimens were used to study the influence of the PP band on the flexural, shear, and torsional behaviors of brick masonry. In the flexural tests, the results show that the average load-carrying capacity at ultimate failure and deflection at first crack of the PP band specimens was 1.7 and 1.62 times, respectively, higher than those of non-PP band specimens. In the shear tests, the tests on the strengthened specimens showed an increase in the shear strength for all pre-compression ranges of 0.2–0.6 N/mm2. However, it was not significant. Similarly, the initial stiffness was not significantly affected by the pre-compression level in both the reinforced and unreinforced cases. In the torsion tests, the improvements in the average load-carrying capacity and deformation ability at the first crack were 1.21 times and 1.47 times, respectively. In the reinforced specimens, at ultimate failure, a slight increase in load was observed, but it did not exceed the initial peak load.