Research

Climate change is currently one of the greatest challenges of our time. The influence of the building sector is enormous, with a raw material consumption of 47.5 gigatonnes per year and an energy consumption of 40% of the total energy consumed worldwide. According to the BMK report Energy in Austria 2021: Facts and Figures, the provision of space heating and air conditioning consumes almost 24% of the total final energy demand. Progress with regard to the environmental efficiency of residential and service buildings is therefore particularly crucial in this sector. 30% of Austrians live in buildings constructed in the sixties and seventies, another 30% in houses older than 40 years. The newly constructed buildings are responsible for only 10-20% of the total energy consumption due to the high demands on thermal insulation. 80% of the energy is consumed by older existing buildings. In Austria, about 1.9 million residential units are in a thermally insufficient condition and thus in need of renovation. The renovation of existing buildings and in particular the renovation and thermal refurbishment of the façade is therefore currently one of the most important sub-sectors of the building industry. The advancement of research as well as the large-scale establishment of environmental and economically attractive systems is therefore indispensable. The aim of this project is to research the basics for the development of serially prefabricated systems (e.g. from renewable raw materials). With the help of these fundamentals, a basis is to be created for the industry in order to be able to offer innovative and, in particular, environmental competitive alternatives to the currently largely used composite thermal insulation systems with corresponding capacities on the market in the future. The focus will be on resource-efficient and recyclable systems and building materials as well as efficient and economical production and installation. Accompanying the research into technical solutions, an ecological and economic analysis will be carried out in order to be able to quantify the potential accordingly.

The content of the project is to develop a research-based, robotic, additive manufacturing (3D printing) process for wall components using bio-based raw materials, with the raw materials coming primarily from by-products of the paper, starch and sawmill industries. A mixture of lignin, starch and sawdust is printed, either in powder form or using a granulate as an intermediate product. The underlying problem concerns four issues: (1) the worldwide shortage of non-renewable and renewable raw materials (2) the current main use of inorganic building materials (concrete and steel) in the construction industry as well as the (3) to date still inefficient use as well as also missing circular approaches in the use of renewable raw materials and (4) the low productivity in the construction industry. The two overarching objectives of the proposed R&D project are: (1) Development of a bio-based, fully recyclable material consisting exclusively of by-products of the paper, starch and sawmill industries and (2) Development of a robotic additive manufacturing process for wall components suitable for the use of the developed material. The combination of the novel material and the additive manufacturing process, which allows a radical simplification of the production of individual components, can result in an enormous technological leap in the use of renewable resources compared to the current state of the art and practice. Wood waste could be processed directly without complex intermediate processing steps. By mixing it with the developed “biomix” (biological glue) and, if necessary, other additives, enabling different modifications such as better water or fire resistance, a new type of building material is created. Based on previous research mixing all components in a dry sate is possible, therefore allowing for a dry extrusion before water is added as final step before compression under additional heat treatment. By using only by-products of the wood industry, the degree of utilisation can be increased from currently max. 60% (for sawn timber) to >90%. With the completion of the research project, comprehensive knowledge on the production processes as well as the chemical and mechanical properties of the new material will be available. This expertise will be supplemented by the acquired knowledge on the additive manufacturing process using bio-based materials and a fully functional additive manufacturing tool for mounting on industrial robots (and also suitable for gantry systems). The fabrication of up to 200mm thick walls will be possible. Furthermore, extensive LCA data will be available, considering raw material supply and transport (according to EN 15804: A1-A2), the manufacturing process (A3), deconstruction and demolition (C1) as well as a forecast for the use stage (B). The results will be shown within a full-scale 3m long and 3m high demonstrator wall. With this project, a completely new dimension in terms of automation, recyclability, and biological resource-efficient construction will be reached.

The aim of the project is basic research about the optimization of prestressed Carbon fibre Reinforced Polymer (CFRP) reinforced Ultra-High Performance Concrete (UHPC) slab elements for a best possible material utilization. In the beginning the building component geometry is optimized. Furthermore the bond behaviour of CFRP reinforcement elements and the prestressing process is investigated. Finally the load bearing behaviour of such elements will be examined in numerical and experimental full scale investigations.