Tests on prototype pretensioned natural stone beams

Stone has over millennia been used for structures which naturally develop compression under gravity loads. This study focuses on segmental stone beams with artificially induced compression. Prototype specimens were fabricated using epoxy adhesive longitudinal shear transfer between prestressed steel strands and pre-cut Valange limestone blocks mortar inter-block joints. Each specimen was by a single strand, to enable focus the fundamental mechanics. strand tensioned against stone, then released after became structurally active, so this is form of pretensioning eliminates external anchors elastic shortening losses, enables agile construction because it can be implemented either at factory or site. Specimen details informed pullout tests. One type entailed concentrically pretensioned square-section blocks, other eccentrically rectangular-section blocks. concentric-strand strain-gauged near both ends identification zone, while an eccentric-strand instrumented midspan strain displacement gauges quantify pretensioning-induced camber strains. Vibration tests conducted specimens, tested ultimate in three-point flexure subjected fire. The results reveal good damping, high consistent modulus based alternately local global data, beneficial delay load-induced cracks joints due protection extended period limit state load gradual spalling peak zone followed dominant crack asymmetric about midspan. These strongly hint viability low-carbon floor applications.