Volume 26, Issue 4 (July 1998)
A Strategy for Mimicking Voids in Historic Masonry
This paper examines the issue of voids in historic masonry. Tabby, an historic, concrete-like substance composed of lime, sand, oyster shell, and water, was selected as the masonry to examine. This study had a two-fold purpose: to develop a strategy for mimicking voids using tabby as a test bed for employment in other masonry contexts, and to replicate the appearance of historic tabby while eliminating the liabilities associated with opea voids in the Masonry matrix. To this end, glass beads were introduced into the tabby mix. The desired result was a product that appeared to have voids, but in fact did not. Test results indicated that the visual appearance of original tabby is mimicked due to the translucent quality of glass, and the structural instability factor is reduced by effectively filling the voids without altering the physical characteristics or producing additional liabilities.