Three prizes for young engineers Foundation of the Chamber of Engineers of Lower Saxony awards prizes for final theses at TU Braunschweig
Three theses – one dissertation and two bachelor’s theses – from the Faculty of Architecture, Civil Engineering and Environmental Sciences at Technische Universität Braunschweig received awards from the Foundation of the Chamber of Engineers of Lower Saxony this year. Innovative methods for investigating the quality of asphalt pavements, the settling behaviour of sediments as a function of salt concentration, and experiments on the mechanical properties of rock salt relevant to the search for a final repository were the focus of the three scientific theses. The prizes go to Dr Johannes Büchner, Ellen Krahl and Gerrit Bremer.
Simple and fast quality testing of asphalt pavements with small quantities of material
Dr Johannes Büchner receives the Foundation’s award for his dissertation at the Braunschweig Pavement Engineering Centre. Photo credit: Dr. Johannes Büchner/TU Braunschweig
In the context of his dissertation “Prüfung von Asphaltmastix im Dynamischen Scherrheometer”, written at the Braunschweig Pavement Engineering Centre under Professor Michael P. Wistuba, Dr. Johannes Büchner developed a testing methodology to carry out quality tests of building material components with small material samples. The bituminous binder used in asphalt pavements and the fine proportion of mineral aggregates (filler) have a significant influence on the service properties and durability of asphalt roads. This mixture of binder and filler is called mastic asphalt. With the new test method in the dynamic shear rheometer, a universally applicable measuring instrument, the service behaviour of mastic asphalt can be examined easily, quickly and with small quantities of material in the laboratory. In this way, a clear quality assessment of the building material components and at the same time a prognosis of the resulting asphalt properties can be made.
Read more on the faculty’s website.
The dissertation on the TU Braunschweig publication server.
Estuaries into the sea under the microscope: When clay minerals form flocs in water
Ellen Krahl received an award for her Bachelor’s thesis, which was written in the Department of Hydraulic Engineering and River Morphology at the Leichtweiß Institute for Hydraulic Engineering and Water Resources (LWI). Photo credit: Ellen Krahl/TU Braunschweig
In her Bachelor’s thesis, written in the Department of Hydraulic Engineering and River Morphology at the Leichtweiß Institute for Hydraulic Engineering and Water Resources (LWI), Ellen Krahl studied the settling behaviour of suspended clay minerals. This settling behaviour varies depending on the salt concentration of the water in which the clay minerals are suspended. At higher salt concentrations, flocculation can occur. Krahl therefore set up an experimental test rig on which she was able to qualitatively and quantitatively investigate the onset of flocculation of clay minerals. Her results clearly show that the critical salt concentration for flocculation is in the range of the salt concentration of surface waters, so that flocculation can be expected in almost all coastal river courses. This information represents an important finding in the management of estuaries, i.e. river mouths flowing into the sea.
Read more on the faculty’s website.
Relevant for repository search: behaviour of rock salt as a host rock
Gerrit Bremer won the Foundation Prize for his Bachelor’s thesis at the Institute for Geomechanics and Geotechnics. Photo credit: Gerrit Bremer/TU Braunschweig
In his Bachelor’s thesis at the Institute for Geomechanics and Geotechnics, Gerrit Bremer dealt with the mechanical properties of rock salt. Using triaxial compression tests, he investigated the direction-dependent behaviour of rock salt from flat bedding in a series of tests. In addition, ultrasonic travel time measurements were also carried out to gain a more precise insight into the crack development process. His work is relevant to the search for and evaluation of repositories for highly radioactive material. To ensure long-term safe containment, the favourable overall geological situation at the potential site is a fundamental prerequisite. For the German search for a repository, rock salt, mudstone and crystalline rock are considered as suitable host rocks for this purpose (BGE, 2020).
Read more on the faculty’s website.
About the Foundation of the Chamber of Engineers of Lower Saxony
The foundation annually honours graduates for their special practice-oriented scientific engineering achievements at Lower Saxony’s university locations. The main aim is to make the excellent final theses known to the public.
Further information: www.stiftung-ingkn.de