Characteristics of CFRP strengthened masonry wallettes under concentric and eccentric compression

Abstract

Strengthening of masonry walls using Fibre Reinforced Polymers (FRP) sheets have shown to improve the lateral (in-plane and out-of-plane) resistance and deformation characteristics. While the improvements in shear and flexural resistances of FRP strengthened masonry are well understood, their simultaneous influence on the compression resistance of the masonry is not well explored. Therefore, this study aimed to understand the contribution of Carbon Fibre Reinforced Polymer (CFRP) strengthening on the concentric and eccentric compression strength and deformation characteristics of masonry wallettes. Two types of clay bricks were used to construct the masonry wallettes with a commonly used cement-sand mortar. In total, 36 masonry wallettes were experimentally tested under concentric and eccentric compression. The tests results are presented and discussed in terms of observed failure modes, compressive strengths and axial deformation characteristics derived. The failure of the CFRP strengthened wallettes were mainly attributed by crushing failure of masonry. The transverse stain readings of CFRP sheets on the wallettes confirm that the composite action exists in the CFRP strengthened masonry wallettes. Further, CFRP strengthened wallettes tested under concentric compression have shown to improve the compression resistance only about 10–20 %. The stiffness and ductility of the wallettes strengthened with CFRP has improved (20–30 %) compared to the un-strengthened wallettes. Therefore it can be said that, although the CFRP application can improve the shear and flexural resistances, it does not significantly enhance the compressive strength and ductility, as the compression failure was governed by masonry crushing.

Keywords

• Masonry
• Fibre reinforced polymer
• Concentric compression
• Eccentric compression
• Stress-strain curve
• Ductility