Conservation of rammed earth works in the Islamic Fortified Complex of Calatayud (Spain)

Abstract

The Islamic Fortified Complex of Calatayud is one of the most singular examples of al-Andalus military architecture. The Complex has a perimeter of more than four kilometers and is defended by five castles. It was used and maintained as a military structure until the twentieth century. The chronology of its different works has been recently put into question. The Complex owes its singularity to the fact that it is primarily constructed out of gypsum (SO 4Ca(2H 2O)), obtained from the rock where the site is located. This fact sets is apart from most other examples of rammed architecture, where lime (CO 3Ca) is the main building material. This paper presents the results from two consolidation campaigns, dating from 2007 to 2011, which resulted in the first typological classification of not only the construction technologies found on-site, but also the conservation techniques used. This period also provided opportunity for testing the suitability of some of these techniques using historical material samples. © 2012 Taylor & Francis Group, London.