Strengthening of Masonry Elements by FRP: Influence of Brick Mechanical and Microstructural Properties

Abstract:

In this paper, the effect of several brick and mortar mechanical and microstructural parameters on the maximum debonding force of the same glass fiber reinforced polymer (GFRP), applied on different bricks and on corresponding masonry panels, was investigated. GFRP sheets were bonded by epoxy resin to four different types of solid fired-clay brick and four types of masonry panels, manufactured using the same bricks and a natural hydraulic lime mortar. The reinforced specimens were subjected to bond tests to evaluate the maximum debonding force. Bricks and mortar were characterized in terms of compressive strength (in the case of bricks, along two different orthogonal directions), surface roughness and pore size distribution. Based on the results of the study, alongside brick mechanical properties in different directions, also brick microstructural parameters seem to play a very important role, which should be taken into account for fully explaining the experimental results.

• Periodical: Key Engineering Materials (Volume 624)
• Pages: 330-337
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.624.330
• Online since: September 2014
• Authors: Claudio Mazzotti, enrico sassoni*, Alessandro Bellini, Barbara Ferracuti, Elisa Franzoni
• Keywords: Bond Test, Brick Anisotropy, Mercury Intrusion Porosimetry, Microscopy, Surface Roughness (SR)

References

[1] C. Mazzotti, E. Sassoni, G. Pagliai, Determination of shear strength of historic masonries by moderately destructive testing of masonry cores, Construction and Building Materials, 54 (2014) 421-431.

DOI: 10.1016/j.conbuildmat.2013.12.039

[2] E. Sassoni, C. Mazzotti, The use of small diameter cores for assessing the compressive strength of clay brick masonries, Journal of Cultural Heritage, 14S (2013) e95-e101.

DOI: 10.1016/j.culher.2012.11.027

[3] P. Carrara, D. Ferretti, F. Freddi, Debonding behavior of ancient masonry elements strengthened with CFRP sheets, Composites: Part B, 45 (2013) 800-813.

DOI: 10.1016/j.compositesb.2012.04.029

[4] N. G. Shrive, The use of fibre reinforced polymers to improve seismic resistance of masonry, Construction and Building Materials 20 (2006) 269-277.

DOI: 10.1016/j.conbuildmat.2005.08.030

[5] G. Vasconcelos, P.B. Lourenço, In-plane experimental behavior of stone masonry walls under cyclic loading. J. Struct. Eng., 135 (2009) 1269-1277.

DOI: 10.1061/(asce)st.1943-541x.0000053

[6] R. Fedele, G. Milani, A numerical insight into the response of masonry reinforced by FRP strips. The case of perfect adhesion. Composite Structures, 92 (2010) 2345–2357.

DOI: 10.1016/j.compstruct.2010.03.014

[7] I. Cancelliere, M. Imbimbo, E. Sacco, Experimental tests and numerical modeling of reinforced masonry arches, Engineering Structures 32 (2010) 776-792.

DOI: 10.1016/j.engstruct.2009.12.005

[8] R. Fedele, G. Milani, Three-dimensional effects induced by FRP-from-masonry delamination. Composite Structures, 93 (2011) 1819-1831.

DOI: 10.1016/j.compstruct.2011.01.022

[9] C. Faella, E. Martinelli, S. Paciello, G. Camorani, M.A. Aiello, F. Micelli, E. Nigro, Masonry columns confined by composite materials: Experimental investigation. Composites: Part B 42 (2011) 692–704.

DOI: 10.1016/j.compositesb.2011.02.001

[10] R. Fedele, G. Milani, Assessment of bonding stresses between FRP and masonry pillars during delamination tests, Composites Part B: Engineering, 43 (2012) 1999-(2011).

DOI: 10.1016/j.compositesb.2012.01.080

[11] M.R. Valluzzi et al., Round Robin Test for composite-to-brick shear bond characterization, Materials and Structures 45 (2012) 1761-1791.

[12] I. Basilio, R. Fedele, P.B. Lourenço, G. Milani, Assessment of curved FRP-reinforced masonry prisms: experiments and modeling, Construction and Building Materials, 51C (2014) 492-505.

DOI: 10.1016/j.conbuildmat.2013.11.011

[13] I. Iovinella, A. Prota, C. Mazzotti, Influence of surface roughness on the bond of FRP laminates to concrete, Construction and Building Materials, 40 (2013) 533-542.

DOI: 10.1016/j.conbuildmat.2012.09.112

[14] C. Mazzotti, B. Ferracuti, A. Bellini, Experimental bond tests on masonry panels strengthening by FRP, Proceedings of the 6th International Conference on FRP Composites in Civil Engineering - CICE 2012, Rome, 13-15 June 2012, 1-8.

DOI: 10.1016/j.compositesb.2015.05.019

[15] E. Sassoni, C. Mazzotti, G. Pagliai, Comparison between experimental methods for evaluating the compressive strength of existing masonry buildings, Construction and Building Materials (in press).

DOI: 10.1016/j.conbuildmat.2014.06.070