Compression and Cyclic Shear Behavior of Lime Mortar Brick Masonry

Abstract

Most of the British regime engineered heritage brick masonry in northern India is either purely in lime mortar or in lime-surkhi (crushed brick aggregate) mortar. Lime mortar constituting majorly of historical brick masonry stock and influences substantially the dynamic characteristics was investigated. The heritage buildings are highly vulnerable against seismic actions especially in the highly active tectonic regions of Himalayan foothills. Material properties of Historic Unreinforced Brick Masonry (HUBM) in lime mortar are critical to be evaluated for assessment but it is difficult to test the in-situ constituents due to intervention constraints governed by civic bodies on such heritage structures and hence exhaustive testing has been carried out on contemporary lime masonry. Compression tests have revealed the design, yield, ultimate strength and feasible inelastic material properties suitable enough to characterize the cyclic behavior of historical brick masonry in India. Elastic modulus, shear modulus and Poisson ratio have been evaluated to be on the lower side as compared to contemporary mortars constituted masonry. Parameters such as damping, hysteresis behavior, energy dissipation and stiffness degradation characterizing the seismic behavior in elastic and inelastic range suggested the improved performance of brick masonry with increase in compressive strength of lime mortar.