Numerical Evaluation of Mechanical Parameters Role in GFRP Strengthened Cobblestone Masonry Walls

Abstract:

The use of a GFRP (Glass Fiber Reinforced Polymers) mesh, embedded as a reinforcement in a mortar coating on both wall sides, proved to be effective and reliable in increasing the masonry wall resistance and the plastic deformation capacity.In this study, a NL finite element model, developed to predict the in-plane behaviour of masonry walls strengthened by means of this technique, is refined and used in an extensive parametric study. Numerical results were compared with diagonal compression test data on URM and RM cobblestone masonry samples, showing good agreement. The masonry panel and the mortar coating were modelled as isotropic homogeneous materials with a smeared crack approach, whereas the GFRP reinforcement was modelled as a mesh of truss elements. Properties assigned to materials were derived from experimental tests.The parametric study performed before on some involved mechanical properties, considering a standard range of variation, is now extended to other parameters. Moreover, the combined variation of different properties is considered. The actual contribute of each component (masonry, GFRP mesh, mortar) on some macroscopic parameters (strength and ductility of the specimen) is evaluated.The parametric analysis highlights the important role of the GFRP mesh not only on the peak load increment but also on the post-peak behavior and, in particularly, on the ductility increment of the reinforced masonry panel. These results can address the optimization of the intervention technique and the deliverable of operative guidelines for practitioners.

• Periodical: Key Engineering Materials (Volume 747)
• Pages: 504-511
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.747.504
• Online since: July 2017
• Authors: Natalino Gattesco, Alessandra Gubana*, Massimo Melotto
• Keywords: Cobblestone Masonry, GFRP Mesh, NL FEM Analysis, Strengthening Intervention

References

[1] Tomaževič, M. & Apih, V. 1993. The strengthening of stone-masonry walls by injecting the masonry-friendly grouts. European Earthquake Engineering 1: 10–20.

[2] Valluzzi, M. R., Binda, L., & Modena, C. 2005. Mechanical behaviour of historic masonry structures strengthened by bed joints structural repointing. Constr. and Building Mat. 19(1): 63-73.

DOI: 10.1016/j.conbuildmat.2004.04.036

[3] Triantafillou, T. C. 1998. Strengthening of masonry structures using epoxy-bonded FRP laminates. Journal of composites for construction 2(2): 96-104.

DOI: 10.1061/(asce)1090-0268(1998)2:2(96)

[4] Valluzzi, M.R., Modena, C. & de Felice G. (2014). Current practice and open issues in strengthening historical buildings with composites. Materials and structures 47: 1971-(1985).

DOI: 10.1617/s11527-014-0359-7

[5] de Felice, G. 2016. Pros and cons of mortar-based composites for strengthening historic structures. SAHC 2016 Conference, Leuven, Belgium.

DOI: 10.1201/9781315616995-40

[6] Gattesco, N. & Boem, I. 2014. Out-of-plane behaviour of masonry walls strengthened with a GFRP reinforced mortar coating. Proc. of the 9th int. Masonry Conference, Guimaraes, Portugal.

DOI: 10.1201/9781003098508-88

[7] Gattesco, N. & Boem, I. 2015. Experimental and analytical study to evaluate the effectiveness of an in-plane reinforcement for masonry walls using GFRP meshes. Construction and Building Materials 88: 94-104.

DOI: 10.1016/j.conbuildmat.2015.04.014

[8] Gattesco, N., Gubana, A. & Melotto, M. 2016. GFRP to strengthen masonry walls: numerical analysis and evaluation of the different mechanical parameters role, SAHC 2016 Conference, Leuven, Belgium.

DOI: 10.1201/9781315616995-47

[9] RILEM, T. C. 1991. LUM B6 Diagonal tensile strength tests of small wall specimens. RILEM Recommendations for the testing and use of constructions materials, 488-489.

DOI: 10.1201/9781482271362-309

[10] Brignola, A., Frumento, S., Lagomarsino, S. & Podestà, S. 2008. Identification of shear parameters of masonry panels through the in-situ diagonal compression test. International Journal of Architectural Heritage 3(1): 52-73.

DOI: 10.1080/15583050802138634

[11] Vecchio, F. J. & Collins, M. P. 1986. The modified compression-field theory for reinforced concrete elements subjected to shear. ACI Journal Proceedings 83(2).

DOI: 10.14359/10416

[12] Feenstra, P. H. 1993. Computational Aspects of Biaxial Stress in Plain and Reinforced Concrete. PhD Thesis, Delft University of Technology, Netherlands.

[13] Hordijk, D. A. 1991. Local Approach to Fatigue of Concrete. PhD Thesis, Delft University of Technology, Netherlands.