Workshops Sponsored by IA-FraMCoS

High-Performance Fibre-Reinforced Cement-based Composites (HPFRCC) for Future Infrastructures, 26-31 July 2015, Dresden, Germany

The summer school was organized at the Technische Universit├Ąt Dresden, Germany, by the Institute of Construction Materials under the coordination of Prof. Viktor Mechtcherine. The goal of the Summer School was to bring together PhD students and post-doctoral researchers working with novel HPFRCC and provide a comprehensive overview of the state-of-the-art research in the field of the material design and testing, use in new constructions, as well as for strengthening and repair of buildings and infrastructure.

The summer school had its focus on two types of HPFRCC, namely on Textile Reinforced Concrete (TRC) and Strain-Hardening Cement-based Composites (SHCC). Despite their different reinforcing principles, both composites have a common feature: Formation of multiple, fine cracks under increasing tensile loading, resulting in a high strain capacity and narrow crack widths. TRC is a composite material consisting of a finely grained cementitious matrix and a continuous two-dimensional reinforcement made of high-performance filaments, while SHCC has a dispersed reinforcement in form of short high-performance polymer micro-fibres. These composites can been used for production of filigree construction elements such as thin shell-elements or facade panels, for new constructions as well as for retrofitting and strengthening existing structures that are prone to aggressive environmental loading or severe mechanical loading scenarios, e.g. earthquakes or impact.

The high number of applications from all over the world says much about the actuality and high interest on this topic. More than 100 applications were received, which made the selection of just 30 highly qualified participants a challenging task. The selected 27 PhD students and 3 post-doctoral researchers came out of 22 countries. The summer school program consisted of two main parts: lectures and exercises. The invited guest lecturers from Italy, Japan, USA and Germany, among them such top experts as Professors Marco Di Prisco, Barzin Mobasher, Minoru Kunieda and Volker Slowik, shared their knowledge and experience on topics related to mechanical characterization, material modelling, structural design and strengthening, durability, building physics and architectural design. For the lab exercises the participants were divided in compact teams. In the first exercise, the fresh-state behaviour of TRC matrix and SHCC mixtures was tested, and specimens were produced for subsequent mechanical testing. In the next exercise, a series of fracture mechanical experiments was performed, which consisted of quasi-static and dynamic tension tests on composite specimens, and also yarn and fibre pullout tests for describing the interaction between matrix and fibre reinforcement. For a better interpretation of the results and for visualizing the failure mechanisms on microscopic level of observation, ESEM sessions were conducted. Subsequently, the teams performed a complete evaluation of the obtained results and presented one of the considered topics on the last day of the Summer School. For rounding up the event and for letting the participants take home additional impressions, a Dresden city tour as well as a sightseeing of the Saxon Switzerland were organized.

The organizing team enjoyed working with enthusiastic young researches, while the positive feedbacks from the participants confirmed the general impression of a successful event. The Summer School enabled an excellent exchange of experience in both ways and opened gates towards future collaborations.

Modeling of tensile fracture or compressive damage in quasi-brittle materials

Will bring together researchers and scientists working on new developments and applications applied to the numerical modeling of the tensile fracture and the compressive damage in quasi-brittle materials. In particular, cohesive fracture or damage models applied to concrete materials or structures subjected to static, dynamic, seismic or fire loading conditions.

The methods include (but not limited to): Finite or (scaled) boundary element methods, meshfree methods as well as approaches considering random heterogeneous material behavior.

The materials/structures include (but not limited to): Normal or high performance concrete, plain or fibre reinforced concrete, RC structures, concrete-reinforcement interfacial behavior, FRP-concrete bonded joints and FRPstrengthened concrete structures or hydraulic fracture of concrete dams

Final Report