Christensen, Jacob Ellehauge1; Hertz, Kristian Dahl2; Brunskog, Jonas3; Kjær, Martin V.5
1 Section for Building Design, Department of Civil Engineering, Technical University of Denmark2 Department of Civil Engineering, Technical University of Denmark3 Department of Electrical Engineering, Technical University of Denmark4 Acoustic Technology, Department of Electrical Engineering, Technical University of Denmark5 Aarhus Grontmij A/S
Super-light structures is a newly developed and patented construction principle for concrete structures. It combines some of the desirable properties of normal strong concrete and lightweight aggregate concrete in order to improve the utilization of the materials and to design improved concrete structures and elements. The super-light slab element in the present research is developed as a holistic design including all relevant disciplines. The element is based on wellknown technologies and materials, which have been used for millenniums, namely compression arches and lightweight expanded clay aggregate (leca) along with a newly developed technology called pearl-chain reinforcement, which is a system for post-tensioning. Here, it is shown how to combine these technologies within a precast super-light slab element, while honoring the requirements of a holistic design. Acoustic experiments in a controlled laboratory environment have been conducted with the element in order to evaluate its performance in airborne and impact sound insulation. These results have been employed in simulations of the flanking transmission to estimate the in-situ performance of the super-light slab element. The flanking transmission has been done both in a standard room consisting of precast concrete elements and as a parametric study in order to estimate the accuracy of the used model. Experiments on the ultimate limit state regarding moment, shear and pull-out resistance is carried out for the super-light element. As a part of the same test series elastic behaviour of the super-light element is also investigated. This is done to verify that requirements and methods supplied by design codes can be applied to the element with sufficient accuracy. In addition, the super-light slab element has been exposed to a standard fire test. A demo project, where a variation of the super-light element is included as indoor pedestrian bridges, has been designed and constructed. The support system was complicated and included a high amount of point supports. This required a high degree of versatility of the super-light element, as several known technologies were integrated and developed for the super-light element, in order to construct the pedestrian bridges.