Measuring evaporation distribution of mud brick and rammed earth
Abstract
Purpose
Salt weathering is one of the most common agents of decay of Central Asian earthen sites and is in function of water evaporation from the wall surface. Soon after excavation the earthen walls and the stupa of the Buddhist temple of Ajina Tepa (seventh-eighth century AD) started to deteriorate due lack of protection and surface erosion. The most important issue in the planning of conservation work was to understand such mechanisms and to decrease the effect of salt weathering on structural damage. The purpose of this paper is to discuss these issues.
Design/methodology/approach
Evaporation distribution and salts types were studied on selected walls. In addition, three-dimensional recording of the walls and the stupa was undertaken with digital photogrammetric methods.
Findings
It was clearly found that the intensity of salt weathering in the site is high and some salts such as halite (sodium chloride) are thought to originate from groundwater. On the basis of the results obtained, thick shelter coating with mud brick and mud render was designed and constructed as protective measure for the earthen walls.
Practical implications
Those walls that were most affected by salts weathering and erosion at the base (coving) became structurally less sound and eventually collapsed if not conserved.
Originality/value
The work is the first attempt in the design of a methodology for the selection of earthen repair materials and methods.
Keywords
Acknowledgements
The authors would like to thank Yuri Peshkov of the UNESCO Cluster Office of Almaty and Roland Lin of the UNESCO World Heritage Center for their cooperation, management and suggestion during the UNESCO/Japan Trust Fund Project. Kazuya Yamauchi of the National Research Institute for Cultural Properties, Tokyo gave suggestions from the archaeological point of view. Furthermore, the authors would like to thank the administrators, archaeologists, and engineers of the Academy of Sciences of Tajikistan, the Ministry of Culture of Tajikistan and the Tajik Technical University.
Citation
Fodde, E., Watanabe, K. and Fujii, Y. (2014), "Measuring evaporation distribution of mud brick and rammed earth", Structural Survey, Vol. 32 No. 1, pp. 32-48. https://doi.org/10.1108/SS-06-2013-0025
Publisher
:Emerald Group Publishing Limited
Copyright © 2014, Emerald Group Publishing Limited