WEB Additive manufacturing of continuous fiber-reinforced concrete components for lightweight structuresFriday (25.09.2020) 13:35 - 13:50 P: Processing and Synthesis 2 Part of:
Additive manufacturing is a new tool for creating innovative, cost-effective and feasible structures. The development of this technology is the basis of a current project for the research group “Lightweight Construction in Civil Engineering” at Chemnitz University of Technology.
Therefore a production line with two robots working in a team was examined. One of the robots extrudes concrete, while the other one is used to reinforce the component. Fiber-reinforced-plastics (FRP) are used for this purpose. The focus here is on an innovative manufacturing process. Conventional technology uses rebars with prefabricated impregnated rovings, whereby the resin has already polymerized. The new technology involves the automatic introduction of resin-impregnated fibers into the concrete component at a point in time when the resin has not yet polymerized.The polymerization of the plastic matrix begins with the formation and consolidation of the concrete layers. In addition to the positive bond, the uncured resin creates a material bond between the concrete and reinforcement fibers, as well as between the fibers in the roving/rebar. Due to the positive and material bond, there is a progressive application of force, which leads to a higherbond stress. This increase was demonstrated in several tests. Because of the dimensioning of the materials, own test setups had to be constructed. The pull-out test was based on existing regulations (RILEM and Rehm). The bending tensile tests were carried out on plates. In the pull-out test, the developed fiber-concrete bond was four times higher compared to conventional technologies. An increase in the load-bearing capacity was also found in the bending tensile test. This increase in bending tension leads to an improvement in the load-bearing capacity (≥ 15%) and opens up a wide range of possible applications in fundamental lightweight construction principles.