Abstract:
In Portugal, volcanic rocks are commonly used as concrete aggregates for concrete in Madeira
and Azores Islands and in a lesser extent in the Mainland. Nonetheless, the information about
the potential alkali-silica reactivity of Portuguese volcanic rocks is rather scarce. In order to
ful ll this lack of information and in the scope of a Portuguese research project, four volcanic
aggregates from the Portuguese Mainland and Madeira Archipelago were investigated. For
this purpose petrographic characterization (polarizing microscopy complemented by bulk
chemical analysis and scanning electron microscopy with energy dispersive detector) along
with expansion laboratory tests were carried out. In this paper, results of the investigation are
presented aiming to establish a possible correlation among the results from the used methods.
