Inhaltszusammenfassung

Recent investigations indicate that fiber reinforced plastics can be effectively used to improve strength and stiffness in different load bearing situations especially for timber beams. Different configurations and techniques of FRP reinforcement utilize the materials effectively and ensure a long service life of the selected building system. There are still problems to ensure a high quality of the bond line where the end-anchorage zone is the most sensitive part due to high stress concen...Recent investigations indicate that fiber reinforced plastics can be effectively used to improve strength and stiffness in different load bearing situations especially for timber beams. Different configurations and techniques of FRP reinforcement utilize the materials effectively and ensure a long service life of the selected building system. There are still problems to ensure a high quality of the bond line where the end-anchorage zone is the most sensitive part due to high stress concentration. Therefore, CFRP has been used in this case study externally bonded and also near-surface mounted, placing FRP reinforcement into pre-cut grooves in the tension region of the timber member. To describe the overall performance and the important delamination process in the anchorage zone, tests on small-size timber specimens with various bonding length have been done. To determine the allocation of the strain distribution non-destructive testing measurement by industrial close-range photogrammetry was used. As result of the obtained lab testing, an asymmetric tensile stress distribution with normal conditioned stresses was observed due to the high stiffness difference between the adhesive, timber and reinforcement. The structural performance, the failure modes of the tested specimen and the NDT measurement are presented and discussed in this paper, whereby the limitation of using CFRP strips is controlled by serviceability requirements in terms of overall deflections, crack widths and delamination of the FRP. The applied cohesive zone model shows the possibilities in modern numerical investigation with a good agreement to the test results. » weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
Bauwesen und Architektur

DDC Sachgruppe:
Ingenieurwissenschaften