Enhancement of lateral load resistance of earth walls with GFRP retrofitting

Abstract

Earth buildings are used in many countries, including Latin America, Africa, some part of Asia and southern Europe. These structures are built with thick walls made out of local soil. Earth walls possess heavy weight and comparable strength of other masonry and somewhat brittle behaviour. Earth walls are generally lower in tensile carrying capacity and the flexural strength, thereby susceptible for the most of the natural disasters. However, due to sustainable features associated with earth construction, it has regained popularity all over the world. This includes low embodied energy, better thermal comfort, good natural moisture buffering and attractive appearance. Relatively lower resistance to lateral forces under disaster situation has imposed some questions in the minds of the building planners to introduce earth masonry in their projects. Therefore, the aim of the current study has been focused on performance of earth masonry under seismic forces. Two main types of masonry; Compressed stabilized earth blocks (CSEB) and Cement stabilized Rammed Earth (CSRE) were considered in the current study. The performance of these walls under seismic load was experimentally determined with and without retrofitting (GFRP) methods. Shaking table was used as the main apparatus, which has one degree of freedom with 80kg capacity. A set of small-scale wall panels was made out of CSEB and CSRE and tested under scaled version of EL-Centro (EIC) earthquake north south component. As an output deflection, acceleration behaviour at the bottom, middle and top of the panel, failure modes were determined in the experimental program. According to the experimental results, seismic performance of CSEB and CSRE wall panels with retrofitting was found to be satisfactory. However, the panels without retrofitting have shown crack and failure at 6 Hz.