Implications of sulfur mineralogy and consequences of pyrite oxidation for ground engineering

Abstract

Aggressive ground conditions and the physical deterioration of ground and engineering materials can be attributed to a wide range of factors. However, a high proportion of groundwork damage in the engineering environment in the UK results from the presence of sulfur minerals, particularly pyrite, which is unstable under oxidizing and damp atmospheric weathering conditions. The oxidation reactions are complex in that the rate, and the products, depend on the crystalline form and grain size of the pyrite as well as the host mineralogy, the rock fabric and the environmental conditions, including exposure to weathering action brought about by engineering works. The possibility of changes in the potential for pyrite oxidation during and after construction therefore need to be considered to prevent any negative impacts on engineering design and construction. This paper reviews the implications of sulfur minerals, especially of pyrite oxidation, with reference to engineering situations in which pyrite oxidation may have a significant negative impact. Changes in the potential for oxidation because of ground engineering works and strategies for avoiding problems are also considered. Thematic collection: This article is part of the Sulfur in the Earth system collection available at: https://www.lyellcollection.org/topic/collections/sulfur-in-the-earth-system