Assessing the suitability of local earth resources for use in clay barriers to protect historic masonry in Pompeii

This paper presents a case study for the testing of locally available resources selected to form a clay barrier. This is a promising technique for protecting historic masonry from ground moisture intrusion. There are several historical precedents for the use of calcareous, clayey soils to form moisture resilient barriers in architecture. More recently, specialised bentonite mixtures have arrived on the market. Assessment protocols for suitable barrier material will help establish general codes and the potential for this technique to make use of locally available resources, either in their raw state or in mixtures. In this project, a variety of different geo-materials are collected from around Pompeii to test their suitability for use in a barrier installation on a tomb in the archaeological site. The methodology consists of laboratory tests used in the assessment of barrier material for landfill engineering, and rapid tests used in earth construction. A mixture of a calcareous clay and a sand produced barrier material with suitable properties. The methodology can form the basis of assessments elsewhere, to further develop the potential of using locally available geo-resources for conservation and construction projects.