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

Additional information

Notes on contributors

Franco Di Fabio

Franco DI FABIO. PhD, graduated in Structure Engineering in 1997 from University of L'Aquila. Researcher at the Department of Civil, Building and Environmental Engineering of University of L'Aquila from 2004. The research field is the evaluation of seismic vulnerability of reinforced-concrete and masonry structure. Teacher of the course “Masonry building” and of the Second Level Master in “Seismic Engineering” at the University of L'Aquila”.

Amedeo Gregori

Amedeo GREGORI. PhD, ACI member, is a Researcher at the Department of Civil, Building and Environmental Engineering, University of L'Aquila, Italy. He's Visiting Researcher at the Center for Advanced Cement based Materials (ACBM), at the Northwestern University, Chicago, USA . He teaches “Special Constructions” and “Design of Structures” at the University of L'Aquila, where he also teaches at the Second Level Master Course in “Seismic Engineering”. His research interests include structural behavior of high-performance concrete and materials, nondestructive testing, rheology, international bulding codes, seismic engineering.

Matteo Totani

Matteo TOTANI. Graduated in Civil Engineering in 2012. PhD student at the Department of Civil, Building and Environmental Engineering of University of L'Aquila from 2013. Research interests: seismic behavior of masonry structures, retrofitting techniques and innovative seismic devices.