2011
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Gaston Camilleri
Structural strength and repair of masonry walls An Investigation
Abstract
Nine half scale wall specimens were constructed and tested. Each wall specimen was in-plane loaded
by a constant vertical load and a variable racking load, until failure was reached through a stepped
cracked, developed through the mortar joints. This created the ‘pre-damage’ to each wall specimen,
which simulated the possible lateral movements and differential settlement, which are a common
occurrence in the local building typologies. The wall specimens were then repaired, with three
combinations of the four variables, and re-tested. Each variable was tested on three identical wall
specimens, in order to obtain a representative average.
Each specimen was repaired with diagonal reinforcement, in one direction, across and perpendicular
to the induced crack pattern which was unidirectional. The steel reinforcement was inserted into a
chase/groove, known as Near-Surface-Mounted repair, and bonded to the masonry units using an
epoxy resin. The repair was either, one or doubled sided, and the in-plane racking load was either
applied in a monotonic or cyclic pattern. These different variables are based on common constraints
within existing buildings.
The results obtained showed a large increase in the shear capacity of the wall specimens; after the
repair intervention. The one sided repair suffered from an out-of-plane displacement, and failed as a
result of a combination of factors, while the double sided repair did not suffer from out-of-plane
movements and failed as a result of the local crushing failure of the masonry units.