ON-SITE TESTING OF MASONRY SHEAR WALLS STRENGTHENED WITH TIMBER PANELS

In the Institution of Civil Engineers - Structures and Buildings, 174(5)

REFERENCE

Giongo I., Rizzi E., Riccadonna D. (2021). On-site testing of masonry shear walls strengthened with timber panels. In Proceedings of the Institution of Civil Engineers - Structures and Buildings 174(5), 389-402. DOI: 10.1680/jstbu.19.00179

Scope and methodology

• Investigate the use of CLT panels connected to masonry walls with mechanical fixings to repair unreinforced masonry (URM) or to strengthen for out-of-plane and in-plane wall response.

• In-plane semi-cyclic quasi-static loading applied to as-built, repaired and retrofitted configurations were undertaken in an existing historic building.

• Timber panels were fixed to the internal side of masonry walls by means of mechanical fasteners.

FINDINGS

• The shear capacity of repaired masonry walls with CLT panels was 20% higher than the original wall capacity. This was obtained with a minimum of 5 mechanical fixings per square metre of wall surface.

• Retrofitted walls with CLT panels and 8 fixings per square metre reached a 40% higher shear capacity than unreinforced walls.

• The displacement capacity of both repaired and retrofitted specimens was significantly larger than the values recommended by current standards for the ultimate limit state.

• Energy dissipation levels were significantly higher in repaired or retrofitted walls than those tested as-built.

• The reinforcement system was effectively engaged only after wall cracking. Selective wall strengthening can be applied without significant alterations of the force distribution among the resisting walls of the building.

• CLT panels were anchored to the ground to inhibited rocking of the panel. The strength and stiffness demands on the hold-down were found to be compatible with the performance of commercial devices commonly used in timber construction.