TY  - CHAP
A1  - Völlmecke, Lars
A1  - Schwendner, Sascha
A1  - Ho, Ai Phien
A1  - Fischer, Jens
A1  - Seim, Werner
T1  - Assessment of nailed connections in existing structures
N2  - This paper presents the development of an assessment scheme for a visual qualitative evaluation of nailed connections in existing structures, such as board trusses. In terms of further use and preservation, a quick visual inspection will help to evaluate the quality of a structure regarding its load-bearing capacity and deformation behaviour. Tests of old and new nailed joints in combination with a rating scheme point out the correlation between the load-bearing capacity and condition of a joint. Old joints of comparatively good condition tend to exhibit better results than those of poor condition. Moreover, aged joints are generally more load-bearing than newly assembled ones.
KW  - Holzbau
KW  - Träger
KW  - nailed trusses
KW  - nailed constructions
KW  - Corrosion
KW  - Preservation
KW  - Re-use
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230609-63615
ER  - 
TY  - CHAP
A1  - Kleiner, Florian
A1  - Rößler, Christiane
T1  - Utilizing Modern FIB/SEM Technology and EDS for 3D Imaging of Hydrated Alite and its Pore Space
T2  - ERICA-CASH II Final Converence
N2  - The exploration of cementitious materials using scanning electron microscopes (SEM) is mainly done using fractured or polished surfaces. This leads to high-resolution 2D-images that can be combined using EDX and EBSD to unveil details of the microstructure and composition of materials. Nevertheless, this does not provide a quantitative insight into the three-dimensional fine structure of for example C-S-H phases.
The focused ion beam (FIB) technology can cut a block of material in thin layers of less than 10 nm. This gives us a volume of 1000 μm³ with a voxel resolution of down to 4 x 4 x 10 nm³. The results can be combined with simultaneously acquired EDX data to improve image segmentation. Results of the investigation demonstrate that it is possible to obtain close-to-native 3D-visualisation of the spatial distribution of unreacted C3S, C-S-H and CH. Additionally, an optimized preparation method allows us to quantify the fine structure of C-S-H phases (length, aspect ratio, …) and the pore space.
KW  - Rasterelektronenmikroskop
KW  - Alit
KW  - SEM
KW  - Focussed Ion Beam
KW  - EDX
KW  - energy dispersive X-ray spectroscopy
KW  - alite
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210702-44555
ER  -