PSI - Issue 44

Guadagnuolo M et al. / Procedia Structural Integrity 44 (2023) 942–949 Guadagnuolo et al. / Structural Integrity Procedia 00 (2022) 000–000

948

7

6. Conclusion The paper analyzes the pullout strength of fibre bar anchors, one of the least studied aspects of the use of FRPs in strengthening structures. The many factors (substrate type, bar diameter, bonding agent, anchorage length, etc.) that influence pull-out resistance are initially examined through an extensive experimental and theoretical state-of-the art. The latter allowed the shortcomings of the current state of knowledge to be better highlighted. All of the analyzed experimental data show that the usual theoretical formulations severely underestimate the actual strength of anchors. The data analysis also showed different behavior between anchors in medium to low-strength concretes compared with those in stronger concretes. The analyses performed led to the conclusion that the gap between the experimental and theoretical strengths can be considered a plus to be added to the theoretical strength, to be evaluated as a contribution to the bond strength along the lateral surface of the bar-concrete interface cylinder. The proposed approach seems to allow a better assessment of anchorage capacity in FRP strengthening systems used to prevent overturning of infill walls in r/c buildings or masonry walls, although further investigation and feedback for other experimental data are evidently needed. Acknowledgements The authors gratefully acknowledge the support provided by Olympus srl, Napoli, Italy. References Achillides, Z., & Pilakoutas, K., 2004. Bond Behavior of Fiber Reinforced Polymer Bars under Direct Pullout Conditions. Journal of Composites for Construction - J COMPOS CONSTR, 8. https://doi.org/10.1061/(ASCE)1090-0268(2004)8:2(173) ACI 440.3R-04, 2017. Guide Test Methods for Fiber-Reinforced. Ahmed, K. S., Shahjalal, M., Siddique, T. A., & Keng, A. K., 2021. Bond strength of post-installed high strength deformed rebar in concrete. Case Studies in Construction Materials, 15(May), e00581. https://doi.org/10.1016/j.cscm.2021.e00581 Ascione, L., Benedetti, A., Borri, A., di Tommaso, A., Feo, L., Frassine, R., Manfredi, G., Monti, G., Nanni, A., Piazza, M., Poggi, C., & Sacco, E. (2020). Italian design guidelines for the strengthening of existing civil constructions using externally bonded fibre-reinforced polymers. Composites in Civil Engineering, CICE 2006, 227–230. Baena, M., Torres, L., Turon, A., & Barris, C., 2009. Experimental study of bond behaviour between concrete and FRP bars using a pull-out test. Composites Part B: Engineering, 40(8), 784–797. https://doi.org/10.1016/j.compositesb.2009.07.003 Barbieri, G., Biolzi, L., Bocciarelli, M., & Cattaneo, S., 2016. Size and shape effect in the pull-out of FRP reinforcement from concrete. Composite Structures, 143, 395–417. https://doi.org/10.1016/j.compstruct.2016.01.097 Barros, J. A. O., 2011. Steel fibre reinforced concrete: Material properties and structural applications. Fibrous and Composite Materials for Civil Engineering Applications, 95–155. https://doi.org/10.1533/9780857095583.2.95 Benmokrane, B., Tighiouart, B., & Chaallal, O., 1996. Bond strength and load distribution of composite GFRP reinforcing bars in concrete. ACI Materials Journal, 93, 246–253. Bertolesi, E., Galli, F. 2012. Use of frp connectors in the reinforcement of concrete and masonry elements. Bachelor thesis, Structural Engineering Department of Politecnico di Milano. http://hdl.handle.net/10589/72796. Boumakis, I., Ninčević, K., Marcon, M., Vorel, J., & Wan-Wendner, R., 2022. Bond stress distribution in adhesive anchor systems: Interplay of concrete and mortar creep. Engineering Structures, 250(September 2021), 113293. https://doi.org/10.1016/j.engstruct.2021.113293 Brown, J. R., Li, M., Tannert, T., & Moroder, D., 2021. Experimental study on orthogonal joints in cross-laminated timber with self-tapping screws installed with mixed angles. Engineering Structures, 228, 111560. https://doi.org/10.1016/j.engstruct.2020.111560 Ceroni, F., Cuzzilla, R., & Pecce, M., 2016. Assessment of performance of steel and GFRP bars as injected anchors in masonry walls. Construction and Building Materials, 123, 78–98. https://doi.org/10.1016/j.conbuildmat.2016.06.124 CNR DT 203, 2006. Istruzioni per la progettazione, l’esecuzione ed il controllo di strutture di calcestruzzo armato con barre di materiale composito fibrorinforzato (in italian). CSA - S806-02, 2002. Design and Construction of Building Components with Fibre-Reinforced Polymers. CSLLPP., 2019. Linea Guida per la identificazione, la qualificazione ed il controllo di accettazione dei sistemi a rete preformata in materiali compositi fibrorinforzati a matrice polimerica da utilizzarsi per il consolidamento strutturale di costruzioni esistenti con la tecnica dell’intonaco armato CRM (Composite Reinforced Mortar). Chen, C., Wang, Z., & Zhou, W., 2022. Experimental investigation on axial compressive behavior of fiber reinforced polymer-reinforced concrete columns confined with external fiber reinforced polymer jackets. Advances in Structural Engineering, 25(1), 14–27. https://doi.org/10.1177/13694332211026225 Chen, W., Meng, F., Sun, H., & Guo, Z., 2021. Bond behaviors of BFRP bar-to-concrete interface under dynamic loading. Construction and Building Materials, 305. https://doi.org/10.1016/j.conbuildmat.2021.124812 Clarke, R. J., Miller, D. A., & Cairns, D. S. (2021). Effect of fiber shape on defect sensitivity of fiber kinking for pultruded carbon fiber composites. International SAMPE Technical Conference, 2021-June, 1211–1222.