Structural Testing Campaign for a 30 m Tall 3D Printed Concrete Tower

Abstract

Digital fabrication with concrete promises a more sustainable and efficient construction industry. However, its implementation is progressing slowly, with hardly any real-scale, load-bearing applications to date. Large-scale structural projects are thus essential to assess the validity of the promise of digital fabrication with concrete. Tor Alva, a 30 m tall tower in the Swiss Alps, is such a project currently being developed to be built in 2024 using digital fabrication with concrete. The tower is a modular system featuring load-bearing 3D Printed Concrete (3DPC) V-columns connecting conventional prefabricated reinforced concrete slabs serving as base and capital. Due to the innovative nature of the columns, structural testing was required to validate their structural integrity. The experimental campaign consisted of a series of structural tests: (i) standard mortar and concrete tests, (ii) compressive loading of a downscaled version of the structural core, (iii) full-scale load tests on a two-metre-tall V-shaped column subjected to vertical and horizontal loading and (iv) direct tensile tests on reinforced 3DPC chords (currently in progress). The standard mortar and concrete tests were needed for 3DPC material characterisation. The compression tests assessed the behaviour of the cross-section under governing compressive load. The overall integrity of the fabrication concept and the connections between the elements were tested with the full-scale load tests. The tensile tests will be carried out to evaluate the performance of reinforced 3DPC chords, which is relevant for columns subjected to bending or tensile forces in case of lateral loading. This paper presents the details of the first three test setups and highlights the main findings of the 3DPC material characterisation and the compression tests.