Characterisation of historical fired clay bricks with small angle neutron scattering

Mechanical properties and performance of fired-clay bricks are strictly related to their microstructure and mineralogical composition. The need for meeting the requirements of a nondestructive or low impact approach aimed at the conservation of cultural heritage objects, is prompting for the search of new analytical methods for their characterisation. Small angle neutron scattering (SANS) is a powerful technique for evaluating and quantifying a statistically representative microstructure of heterogeneous materials. Five historical fired-clay bricks, produced in a manufacturing plant of the Czech Republic, have been investigated. SANS-derived parameters allowed to retrieve the shape of the pore size distribution, characterise the fractal surface of pores, and suggest an empirical relationship between surface area per unit volume of pores and firing temperature.