The “marginal materials” of the river tiber valley—Italy

The building of extensive road networks involves, amongst other things, the need for large amounts of building materials, which must meet special requirements such as quality, quantity and ready availability. Now, however, there is a growing need for alternative or complementary building materials, i.e. of “marginal materials” which are generally easily found very close to large cities. In Latium, and above all in the surroundings of Rome, such marginal materials are being considered for road building in replacement of the traditional “Roman puzzolanas” and alluvial sands that are no longer easily available owing to depletion of sources and to restrictions of various types. This study presents the physico-mechanical characteristics of marginal materials, pointing to the technological processes that may enhance their technical qualities thus making them eligible for replacing traditional materials.