Experimental and numerical investigations on historical masonry wall specimens tested in shear-compression configuration

Abstract

The paper presents the experimental investigation carried out on wall specimens reproducing the ancient masonry of several monumental building located in the old city centre of L'Aquila (Italy) and damaged by the April 2009 earthquake. The wall specimens were prepared in accordance with the traditional technique, using original stone elements and typical poor mortar. Subsequently, the specimens were consolidated with mortar injections. Other specimens were also reinforced with Ultra High Tensile Strength Steel wires applied as coating technique (not wrapped). Shear-compression tests were carried out on the wall specimens to evaluate the effects of the reinforcements both in terms of final stiffness and strength of the specimens. A non-linear Finite Element Model (FEM) was developed to reproduce the experimental tests and to better understand the damage phenomena. The load-displacement curves predicted by the FEM compared quite well with the experimental ones. The failure mode of the specimens was properly captured by the FEM. The effectiveness of the external reinforcement was proved to strictly depend on the coating adhesiveness to the walls surface. The premature debonding of the external reinforcement was demonstrated to cause the fragile post-peak behaviour during both the actual experimental test and the numerical simulations.

Keywords

• historical masonry
• retrofitting
• UHTSS wire
• debonding failure mode,
• experimental tests
• FEM analysis