A two-hinged arch is part of a traditional structural element that can last for thousands of years. This mockup experiment tested two prestressed UHPFRC (Ultra-High-Performance Fibre-Reinforced Concrete) arches with a span of 10.32 m up to failure. Each arch was composed of two semi-arches, which were joined and slightly prestressed to ensure watertightness in the joint. The load acted on one third of the span, inducing eigenshape-like displacements. The first tensile crack appeared under the load at 60 kN, followed by shear cracks and tensile failure in an approximately opposite cross-section. The maximum load reached 170 kN with brittle failure afterwards. The behavior was successfully validated using a 3D finite element analysis and damage-plasticity material model. The mockup experiment proved that upscaling to a real ecoduct arch becomes possible, creating a unique structure with a very long service life.
31 October 2023 in Construction and Building Materials
In this paper, information about cementitious composite materials for further 3D processing is discussed and supplemented. Many of the research in this area focuses primarily on cement composites suitable for 3D printing. Nevertheless, 3D printing is not the only robotic processing technique. Another such a technology is modelling with the help of a robotic arm, which can be used to create various elements that fulfil their original but also aesthetic function. The robotic arm creates, using a variety of sculptural or hand tools, a final unique relief of a given element. Three different cement composite mixtures are discussed and their mechanical, physical and thermophysical properties are evaluated. The research aims to investigate and optimise these composites for robotic sculpturing and 3D printing.