This study aimed to better understand the possible adverse effects of diabase aggregates that contain sulphide minerals and particularly pyrite, in conjunction with the chemistry of mixing water and cement (specifically with regard to the sulphate content) that are used in the production of concrete as well as in the estimate of repercussions that likely they have in the resistance and longevity of concrete.
The programme was assigned to a European firm of Consultant Engineers following a tender competition. The programme included the study of aggregates containing sulphide minerals, the collection and study of concrete cores from existing structures, possibly containing aggregates with sulphide minerals, and the manufacture of mortar bars and concrete prisms with predetermined sulphide mineral content. The mortar bars and concrete prisms were subjected to accelerated ageing.
The study concluded that the presence of sulphite minerals in aggregates caused oxidation of limited extent in the concrete, however without observing any harmful reactions.
003_Pyrite_in_Concrete_Final_report_text.pdf