Effect of manufacturing methods on the decay of ceramic materials: A case study of bricks in modern architecture of Madrid (Spain)

The appearance and main decay forms in the fair-faced brick facades on the University Campus of Madrid's Faculty of Medicine were taken as a starting point to analyse certain building's construction characteristics and the clay and technology used in brick manufacture. The raw materials consisted in a mix of Miocene marl and red Triassic clays from the Spanish province of Jaen. The exposed face of bricks was characterised by a yellowish tone and smooth, uniform texture that afforded perfect dimensioning and inter-brick alignment. In some bricks this texture was lost, with a concomitant colour change, surface roughness increase and loss of material. Laboratory studies through polarised optical microscope (POM), X-ray diffraction (XRD) and field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS) revealed similar composition in all the bricks, firing temperatures ranging between 800 and 850 °C and, with the exception of the exposed surface, not particularly careful manufacture.