Shear-torsion tests on 200 mm hollow core floor

To clarify the interaction of shear and torsion in prestressed hollow core floors, ten service load tests and two failure tests on a 200 mm hollow core floor were carried out. The floor comprised four slab units. It was 4.8 m in width, 7.0 m in length and provided with an opening at one end. The ends of the slabs were simply supported. In each test the loading consisted of four closely spaced point loads on the same line which was perpendicular to the direction of the slab units. The purpose of the tests was to provide experimental data for verification of computer models. For this reason, as many as 120 transducers were used to measure the loads, strains and displacements of the floor specimen. The results were qualitatively as expected: nearly linear response not only in service load tests but also in failure tests until a high load level. The observed failure loads were considerably higher than what was observed in a similar load test on a single slab unit. It was also observed that the trimmer beam next to the opening carried only a small share of the support reaction due to imposed load on the slab supported on the trimmer beam. The rest of the support reaction was carried by the grouted joints between slab units.