Roman cement mortars, one of the typical hydraulic building materials used mainly to decorate facades during the nineteenth
and beginning of the twentieth centuries, exhibit specific performances regarding their workability, physico-mechanical performance
and long-term stability. Their key properties are significant strength along with high capillary porosity, which makes them
interesting materials for a number of applications. Thus, recently the interest in Roman cements has been steadily increasing
e.g. in the field of conservation of architectural heritage.
The microstructure of the hydrated matrix of Roman cement mortars can be directly correlated with their above mentioned macro
properties which are currently assessed within the EU-FP7 project ROCARE. The present paper provides preliminary results of
studies on the microstructure carried out in the frame of ROCARE and based on findings from the former EU-FP5 project ROCEM.
The aims are to contribute to a better understanding and interpretation of the macro properties as a function of age, mortar
formulations and curing conditions of Roman cement mortars. Reference to typical matrix microstructures found in historical
Roman cement mortars is also presented.
The analytical approach is mainly based on SEM-techniques preferentially employed on fresh fracture faces of mortars and pastes,
using both secondary electron (SE) and back-scattered (BSE) detectors. The results are compared to the mineralogical and petrophysical