Abstract:

Binders known as ‘Roman cement’ and with very high hydraulic properties were widely used in Europe and its peripheries in the 19th and early 20th centuries on building façades especially in terms of historicist, eclectic and Art Nouveau architectural styles. It was also used in Istanbul although not as dominantly as in central Europe. Two EU projects centered in Vienna, focus on the reproduction of Roman cement for restoration of historic buildings: ROCEM -Roman Cement to Restore Built Heritage Effectively in 2003-2006 and ROCARE - Roman Cements for Architectural Restoration to New High Standards began in 2009 and still continuing.Roman cements were natural, highly hydraulic binders, produced from marls or clayey limestones. This raw material required only calcinations below the sintering temperature 800-1200 °C and then grinding. Roman cement as a binder must be considered between hydraulic limes and Portland cements. They differ from hydraulic limes in that they do not contain free lime and therefore do not require slaking. They differ from Portland cements in chemistry due to lower calcination temperature. The wide range of temperature results in parts calcined at different degrees, thus parts of the binder show different chemical characteristics. This burning temperature below sintering also gives the material its warm color. They have fast setting times after the addition of water and show minimal shrinkage. The development of strength is slow after rapid setting but compressive strength values may reach those of Portland cements in several months.These production and workability features as well as their warm yellow-pink-brown color put Roman cements in great demand for cost-effective and easy manufacture exterior stuccoes

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