In terms of volume, concrete is the most widely used - and hence still one of the most important - inorganic building materials in the world. Primarily consisting of cement, water and sand or aggregates, concrete is no longer just concrete. In fact, thanks to innovative manufacturing processes and the addition of optimized cements as well as a wide range of additives (aggregates, accelerators, retarders, super-plasticizers, stabilizers, air-entraining agents, etc.), concrete these days can be made with highly specific properties.
With this in mind, our scientists are working intensively on various options to improve concrete formulations based on common standards and to adapt them to suit their intended use. We have a wide range of equipment in our building materials laboratory, such as crushers, mixers and molds, which allow us to test and implement innovative concepts. In order to precisely demonstrate the effects of modifications to formulations on the properties of building materials, also in accordance with the relevant standard, we use appropriate testing equipment and measuring instruments.
Concrete has numerous advantages, for example it is easy to work with and has a high compressive strength. However, its tensile strength is comparatively low, which is a challenge. To compensate for this “weak point,” we are looking at innovative materials and processes that do away with the need for heavy, steel bars as reinforcement.
One of the most common environmental influences that weakens concrete structures such as traffic routes, bridges or airport runways in the long term is damage due to frost and road salt. Furthermore, the damaging alkali silica reaction (ASR) - also known as “concrete cancer” - is a worldwide problem that shortens the useful life of concrete and causes immense costs amounting to several hundred million euros every year. We are also addressing these issues. Based on innovative testing technologies, we are currently working on the development of a method that can already be used in the planning phase to rapidly predict the formation of ASR.
Another of our key research topics is recycling building materials such as concrete, something which has recently gained public attention. In Germany, around 70 percent of waste concrete is currently used to build road beds. According to the true definition of “recycling,” however, this form of use cannot be described as such since no material cycles are closed in the process.
Our experts, on the other hand, have already demonstrated on a laboratory scale that, in addition to pure aggregates, it is also possible to obtain substitute raw materials for making cement from waste concrete. The challenge in the coming years will be to scale up this recycling process for use in industry and to establish it on the market.
Last but not least, we are also working on ways to replace primary raw materials by secondary raw materials. In one project, for instance, we are investigating how we can use ashes from waste incineration plants as a filler in concrete.
Do you have an ambitious project, too? We would be happy to advise you!