Building Materials and Process Engineering | Research

Materials, Processes und Machines

The Building Materials and Process Engineering research field investigates and develops the scientific and technical bases for the extraction of raw materials and the production and processing of building materials. Its tasks and responsibilities essentially result from the close interaction between materials, processes and equipment. The only way to implement effective new solutions or improve existing processes is thus to adopt a holistic view and to engage in close collaboration between the fields of materials science, process engineering and mechanical engineering.

Concrete and mortar

In a multitude of projects, an exceedingly wide range of concrete and other mixes are being developed and improved with respect to their material characteristics and workability parameters. Materials include conventi onal ready-mixed and cast-in-place concrete, self-compacting and ultra-high-performance concrete (SCC and UHPC), fibre-reinforced concrete as well as textile, light-weight, aerated and foam concretes, mineral foams, compounds for dry mortar products, soil mortar and plastic-bound polymer concrete.

Ceramic materials

As the oldest man-made building material, brick must respond to steadily increasing requirements regarding its physical properties. We are working on innovations related to raw materials and the production process so as to keep brick competitive both in terms of its physical properties and its commercial viability.

Regenerative raw materials

This research is also inextricably linked to reducing energy consumption and lowering CO₂emissions in production and processing. We conceive sustainability strategies, investigate potentials and develop approaches to the efficient use of resources and waste materials. Furthermore, increasing efforts are being made to conserve primary resources and to promote building with regenerative raw materials. Related research activities pertain not only to wood, but also to the use of hemp, miscanthus and various types of grain.

It’s the Process that Matters Most

Material analysis

Most road pavements are still built with asphalt, even though the significance of concrete in road construction has continuously increased in the past few decades. Requirements for road infrastructure become more and more demanding due to constantly increasing payloads in truck traffic.

This situation opens up a huge potential for an additional field of research. Conventional asphal grades are continuously being improved and optimised to reflect the ever-changing specifications and conditions for their use. For all material systems mentioned above, the IAB applies state-of-the-art methods of material analysis and standardised construction material tests. Machine measurements are conducted simultaneously to analyse and evaluate sequences of existing process steps.

Basic operations: mechanical and thermal process engineering

Methods and processes studied at the IAB can generally be grouped into a selection of basic operations in the fields of mechanical and thermal process engineering:

Extraction and storage
Conveying and batching
Crushing and grinding
Mixing and classifying
Firing and calcining
Agglomerating and moulding
Reprocessing and recycling

The above list is non-exhaustive because the IAB’s resources enable research into almost all material-related processes. Furthermore, these processes determine the related equipment, which comprises a large number of devices, systems and control components. Our work primarily deals with processing machinery for granular and pasty materials. Crushing, mixing and compaction units must increasingly cope with highly complex material systems. The range of materials under study includes fluids, suspensions, foams and granular materials as well as complex, multi-phase systems that combine the characteristics of several individual phases.

Kontrollgenauigkeit nach Zielstellung

Qualitätssicherungssysteme

Die Entwicklung hochwertiger Qualitätsicherungssysteme stellt ein wichtiges Wirkungsfeld des IAB Weimars dar. Im Zentrum steht dabei die Entwicklung von Mess- und Analysesystemen zur Quantifizierung des Stoffverhaltens. Auf deren Grundlage gewonnene Daten werden anschließend in der Steuerung bzw. Regelung eingesetzt und tragen somit zu einer Qualitätssteigerung in der Produktion bei.

Optische Messmethoden

Besonderes Augenmerk liegt auf den optischen Messmethoden in der Prozessüberwachung. Hier ist der große Anwendungsbereich der Bildverarbeitungssysteme zu nennen, die sich gut in der Qualitätskontrolle einsetzen lassen, da sie wichtige Merkmale wie Textur und Farbstabilität visuell erfassen. Erweitert wird dieser Messansatz durch faseroptische Verfahren, die hochauflösende Temperatur- und Dehnungsmessungen entlang des gesamten Lichtleiters ermöglichen.

Konstruktion

Erfüllt die existierende Ausrüstung das vorgegebene Anforderungsprofil nicht, werden die benötigten Geräte neu entwickelt. Dazu wird das für die jeweilige Grundoperation am besten geeignete Verfahren ausgewählt und unter verfahrenstechnischen Aspekten dimensioniert. Es folgen Konzeption und Entwurf der Maschinen sowie deren eigentliche Konstruktion, die mit der Erprobung unterschiedlicher Ausführungsvarianten einhergeht.

Optimierung

Parallel zur klassischen Entwicklungsarbeit kommen verschiedene numerische Methoden zur Optimierung bestehender und in Entwicklung befindlicher Ausrüstungen zum Einsatz. Auf Basis der analysierten Stoffeigenschaften und jeweiligen Maschinengeometrie werden numerische Modelle des Gesamtsystems abgeleitet, die sowohl das zu verarbeitende Stoffsystem als auch die Maschinendynamik des Gerätes abbilden.

Numerische Simulation

Im Anschluss an eine sichere Modellvalidierung werden mit Hilfe der numerischen Simulation Variantenrechnungen durchgeführt, die einerseits die Voraussetzung für die Weiterentwicklung der jeweiligen Komponenten schaffen und andererseits das Prozessverständnis signifikant erhöhen.