High-Performance Masonry Walls for Energy and Resource Efficient Building Envelopes

Externally bonded reinforcement (EBR) was used to increase load bearing capacity of light weight aggregate concrete (LWA) masonry walls subjected to eccentric axial compression. Ladder type masonry reinforcement, high strength steel wire strips and glass fiber mesh were used for strengthening of eleven, 2.4 m high, 0.5 m long and 0.1 m thick walls. The reinforcement was applied on the dry wall surface and subsequently embedded in mortar, a procedure that saves labor time. The walls were subjected to axial eccentric loading, with an eccentricity to wall thickness ratio between 0.18 and 0.20. Six walls failed through local compression (crushing) at the loading plate, four in flexural compression while one in flexural tension. The walls exhibited limited second order deflections, which partly explains the high frequency of compressive failures. While the experimentally and analytically determined deflection of the walls shows good agreement, the same does not apply to the bending moments. The experimentally deduced bending moment capacity was significantly larger than the analytically deduced bending moment capacity. The possible reasons for this difference are discussed. By using EBR, the vertical load bearing capacity of LWA masonry walls can be enhanced by 30–150%. Compared to existing masonry wall solutions, the thickness of load bearing LWA masonry walls strengthened with EBR can be reduced by 40–60 mm, down to a thickness of 110 mm. The new technique is currently tested in three real-world pilot projects.