Concrete is by far the most widely used building material in the world. Its versatile applicability has made concrete the dominant building material of the 20th century. Thus, can concrete also meet the requirements of the 21st century, where the focus is on sustainability and increasing demands on its technical performance?
Research at the Department of Building Materials of the iBMB at the Technische Universität Braunschweig is dedicated to this question. Hence, the focus is on resource-efficient and high-performance concrete construction. In the sense of a holistic approach, our research covers a broad spectrum, starting from eco-concrete and high-performance concrete, durability and repair of existing concrete as well as digital construction processes through 3D concrete printing (digital concrete). We are guided by the following key questions:
1. Eco-concrete: How do we build sustainably and ecologically - today and tomorrow?
Reducing CO2 emissions across all sectors is a top priority to be successful in achieving the global climate goals. To ensure that concrete construction in the 21st century can be both innovative and resource-efficient, we are researching low-clinker eco- and recycled concretes with robust fresh and hardened concrete properties. An important foundation for this is controllable rheology, which allows for the desired hardened concrete characteristics.
2. High-performance concrete: How do we enhance performance?
Concrete offers an immense variety of possible applications from high-strength concrete to self-compacting concrete to architectural concrete. We are working on various high-performance concretes to enable leaner cross-sections, longer component spans, and/or attractive exposed concrete. Depending on the scope, the focus can be on different properties. These include mechanical and durability-relevant parameters so that the concrete can sustainably meet the high demands in terms of load and design.
3. Existing concrete: How do we maintain our building infrastructure?
Owing to their age, a large number of existing buildings show pronounced damage to the building structure through aging and fatigue, e.g. due to traffic loads. Accordingly, the research at the Department of Building Materials aims to contribute to the preservation of existing concrete structures. The focus is on increasing the residual load-bearing capacity and the service life of load-bearing structures, e.g. with the help of bonded reinforcement in the form of lamellas made of carbon-fibre-reinforced polymers. In addition, the condition of the structure is monitored using diagnostic and monitoring systems as well as predicting degradation using suitable models. Moreover, damage-specific repair strategies are being researched.
4. Digital concrete: How will we build in the future?
Innovative building processes are guided by the idea of merging digital planning, material technology and process engineering. In addition to digitalisation, additive manufacturing offers huge sustainability potential through shape optimisation and force-flow-optimised building structures, which enable highly resource-efficient construction. Therefore, 3D concrete printing represents another key area, which is covered across scales in interdisciplinary projects. From particle bed 3D concrete printing to injection 3D concrete printing and shotcrete 3D printing, we are researching a wide range of new technologies to make a decisive contribution to the construction of the future.
In the section Brief Reports from Research, brief reports from the iBMB and the MPA Braunschweig can be downloaded in PDF format.
Sustainable concretes from locally available raw materials (eco-concrete)
Development of concretes with low global warming potential, good workability, strength and durability from locally available raw materials.
The objectives of the project are:
- the development of concrete formulations with a significantly improved ecological balance with the same technical performance (workability, strength and durability) compared to solutions based on the current state of the art.
- the development of a new model to describe the technical performance of eco-concretes.
- the development of methods for the combined technical and ecological assessment of concretes in relation to the construction task, taking into account the entire life cycle.
At the same time, existing hurdles to the market acceptance of eco-concrete are to be overcome with the help of an innovative, practice-oriented recipe development concept. The existing hurdles include:
- the high material costs resulting from the complex requirements for the concrete constituents of classic eco-concretes (and thus also impairing the environmental balance).
- the difficult workability of eco-concretes due to their very high viscosity.
- the often lower technical performance of eco-concretes, especially with regard to some durability aspects. Finally, the material and methodological solutions developed within the framework of this project are to be validated using two concrete construction tasks as examples.
Participating institutes: Braunschweig University of Technology, Institute for Building Materials, Solid Construction and Fire Protection (iBMB), Department of Building Materials and Bochum University of Applied Sciences, Department of Architecture, Chair of Building Physics and Energy-efficient Construction,
Funding period / duration: January 2021 to December 2022 (2 years)
funded by: Dres. Edith and Klaus Dyckerhoff Foundation
Contact: Jens Brack M.Sc.