Dr.-Ing. Thorsten Leusmann
Fachgebiet Baustoffe und Stahlbetonbau
Beethovenstraße 52
38106 Braunschweig
Telephone: 0531/391-5440
Research project:
Fatigue processes in aged reinforced concrete members strengthened with externally bonded reinforcement made of carbon fiber reinforced polymers
Overloading and aging lead to considerable damage to road structures made of reinforced concrete in Germany. One way to address this problem is strengthening with externally bonded carbon fiber reinforced plastics (CFRP). Externally bonded reinforcement (EBR) increases the resistance of the structural member and counteracts overloading. Furthermore EBR causes a tension release from the interior reinforcement which can extend the lifetime of a reinforced concrete member. The service life extension is influenced by many factors. In addition to damage mechanisms such as fatigue the load- and time- dependent material behavior of concrete, steel, CFRP and their connections has an important influence. To find out at which time failure occurs the distribution of forces between interior steel, EBR and concrete has to be exactly known. The aim of the research project is to develop a predictive method for it.
Publications within the framework of the RTG:
Publications in peer-reviewed scientific journals :
P. Carrara, R. Kruse, D.P. Bentz, M. Lunardelli, T. Leusmann, P.A. Varadya and L. De Lorenzis. Improved mesoscale segmentation of concrete from 3D X-ray images using contrast enhancers. Cement and Concrete Composites, 93: 30-42, 2018..
Conference contribution with publication in conference proceedings:
T. Leusmann, G. Basutkar, M. Lunardelli and D. Lowke. Characterizing the 3D Mesostructure of High Performance Concrete with the help of Computed Tomography. Proceeding RILEM Spring convention and sustainable materials, systems and structures conference 2019.
T. Leusmann and H. Budelmann. Force distribution between interior steel reinforcement and externally bonded CFRP of RC beams under cyclic loading. 8th International Conference on FRP Composites in Civil Engineering (CICE 2016): 14-16 December 2016. Hong Kong Polytechnic University, Hong Kong.
T. Leusmann, H.W. Krauss and H. Budelmann. The hardening process of cement based materials observed by calorimetry and ultrasonic tests. 2nd International RILEM/COST conference on Early Age Cracking and Serviceability in Cement-based Materials and Structures (EAC2), 12.-14.09.2017 Brüssel.
M. Lunardelli, T. Leusmann and H. Budelmann. Improvement of debonding behavior among low strengthconcrete and externally bonded CFRP. CICE 2016 Proceedings (2016).
Conference contribution without publication in conference proceedings:
G. Basutkar, T. Leusmann and D. Lowke. Influence of Aggregate Morphological Characteristics on the Fracture Resistance of High Performance Concrete. The Seventh International Conference on Structural Engineering, Mechanics and Computation, Cape Town, South Africa, September 2019.
Z. Chen, H. Grefe, T. Leusmann, K. Dilger and D. Lowke. Quasi-continuous strain measurement with distributed fibre optic sensors in reinforcement bars and externally bonded CFRP strips at concrete slabs - Experiment and modelling. International Institute for FRP in Construction, FRPRCS-14, Belfast, June 2019.