Roberto Bugini1 and Luisa Folli2
1)  CNR-Istituto Conservazione e Valorizzazione Beni Culturali
via Roberto Cozzi 53, 20125 MILANO (Italy)
2)  CNR-Istituto Conservazione Valorizzazioine Beni Culturali
via Roberto Cozzi 53, 209125 MILANO (Italy)

Keywords: Stone, Brick, Masonry, Romanesque architecture, Lombardy.

Abstract. Romanesque architecture (9th to 13th centuries) was examined in order to classify the masonries and the stone materials employed in the costruction. Four kinds of masonry were identified: rubble of pebbles; rubble of stones; ashlar of stones, brickwork also mixed with pebbles or stones. The lithologies involved are: glacial deposits, coarse grained igneous rocks, gneisses, massive or thin bedded limestones and dolomites, conglomerates, thin bedded sandstones. These stone materials were exploited in different areas of the region and they had a long-lasting influence on the making of masonries in the neighbouring territory. The lack of stone material in the Po plain was overcome using the clays of the alluvial deposits to make bricks. The elements of the masonry are almost always disposed in courses, less or more horizontal, and their thickness depends, in the case of sedimentary rocks, on the natural thickness of each stone bed. The use of mortar (lime binder and sandy aggregate) varies according to the shape and the size of the stones, pebbles and bricks.