The largest financial investment that most people make in their lifetimes is their home. In this context, it is difficult to imagine the impact when homeowners learn that their house has a major structural defect that may render it worthless and may not be covered by home insurance. These situations have arisen in the case of tens of thousands of homes in recent years as a result of the aggregates used in construction not being inert. Since construction aggregates become an integral part of a building structure, they are expected to be stable over the life of the structure. However, an excess of naturally occurring reactive iron sulfides in the rock, is all that it takes to cause devastation within a few years of construction.
How can such major structural problems arise in houses given that developed economies, such as the United States, Canada and Ireland, have well established building codes and standards? How can excess sulfides, mainly pyrite and pyrrhotite, in aggregates be defined and identified in advance and what new tests are needed? When reactive sulfides are discovered, how can the risk of future damage be quantified? These issues and more are explored in some depth in a new book to be published soon. The chapter authors are a combination of geological and engineering practitioners as well as researchers who have spent years studying the underlying science, geochemistry and mechanisms that give rise to these problems.
In keeping with the theme of Pyrite & Pyrrhotite, the book will also feature some innovative research into the use of pyrite as a low-cost film to replace silica in the manufacture of solar cells, as well as the use of pyrite pre-treatment to enhance growth of food crops. Given that pyrite is the most common metal sulfide on earth, it deserves more attention, both from the perspective of preventing its negative impacts on the built environment and in finding more constructive uses for it in our drive towards improved sustainability.