GINELL, WILLIAM S.1* and RAKESH KUMAR1,2. 1Getty Conservation Institute, 1200 Getty Center Drive, Los Angeles CA 90049; 2OptronX Inc., 7450 Tilghman Street, Suite 105, Allentown, PA 18106. - Limestone stabilization studies at a Maya site in Belize.
Stone used in the construction of the 8th-11th
century Maya structures at Xunantunich in Belize is a low strength,
porous limestone that is nearly pure calcium carbonate. Degradation of
archaeologically excavated stone structures in the humid, tropical
environment of Belize is caused mainly by wind and water erosion and
wide cyclic variations of humidity and temperature. However, damage to
the limestone is accelerated to varying extents by the chemical and
mechanical effects of lichens, mosses, algae, fungi, and bacteria that
are endemic to the region. To evaluate the effectiveness of possible
stabilization treatments, tests were conducted in which
stone-penetrating consolidant solutions were applied to limestone
samples, which were then exposed to both sunny and shaded environments
over a period of about four years. The results of these treatments
were evaluated by particle and water erosion resistance measurements
on the aged samples. The effectiveness of several biocides in
controlling the establishment and growth of microflora on the exposed
samples and on in situ, ancient stone walls was also studied. Some
tests were conducted to determine if the organic polymer consolidants
would support, or even accelerate, the growth of microflora on the
stone and how the concurrent use of biocides would affect the results.
Several consolidant solutions were found that could penetrate and
stabilize the usually moist limestone and, in combination with
biocides, would minimize the growth of the local microflora.
Key words: biocides, biodegradation, consolidants, limestone, Maya pyramid conservation