Buckling of GFRP pultruded built-up columns

Presented are the test results of an experimental campaign to investigate the buckling behaviour of pultruded built-up columns subjected to concentric loading. The specimens tested are assembled using four C-shape (off-the-shelf) GFRP pultruded profiles, having the same detailing as strut members in a large FRP structure that was executed in 2009 for restoration activities at the Santa Maria Paganica church in L’Aquila (Italy). This church had partially collapsed walls and no roof after the 2009 L’Aquila earthquake. A total of five columns have been characterised with two different configurations for the bolted connections joining together the C-shapes into the built-up member. Test results are discussed and a comparison is made with closed form solutions for flexural buckling resistance and with Eigenvalue buckling predictions from a (linear elastic) finite element analysis.