Punta Begoña Galleries were built in 1918 in Getxo (Basque Country, North of Spain) but were abandoned in 1960. Nowadays, their conservation state is very poor. In this work, portable Raman spectroscopy was applied to evaluate the original composition and possible deterioration products of the mortars used in the inner walls and those covering the concrete of the ceilings allowing us to select the most appropriate sampling points. In the laboratory, Raman microscopy and Raman imaging, assisted with scanning electron microscopy equipped with an energy dispersive spectrometer (SEM‐EDS), X‐ray diffraction and energy dispersive X‐ray fluorescence (ED‐XRF) imaging, allowed to identify the key compounds to understand the deterioration processes taking place in the mortars of the galleries. The main components of the mortars from the walls were calcite and gypsum. In some cases, alite (Ca3SiO5) and belite (Ca2SiO4) were identified; these components are characteristic of Portland cement clinker. The main components of the mortar covering the concrete were calcite, quartz, aragonite and gypsum. The aragonite identification confirmed the use of beach sand as the aggregate in the mortar. The concrete from the ceiling of the lower gallery is covered with three different mortar layers; the outermost layer is covered with a black crust. In the three mortars, the main components are similar to those used in the mortar covering the concrete from the upper gallery. Thanks to Raman, ED‐XRF and SEM‐EDS imaging, it was possible to map the distribution of the main components through the three mortar layers and also to identify the presence of dolomite {[CaMg(CO3)2]}, which was not possible to detect following single‐point micro‐Raman analyses. Copyright © 2016 John Wiley & Sons, Ltd.

The use of portable Raman is proposed as the modern hammer of architects to inspect protected buildings of the 20th century, where reinforced concrete was used for structures and Portland type cement for mortars/binders in the walls. Two different buildings in the province of Biscay (North of Spain) were selected, the Punta Begoña Galleries, Getxo (1918), qualified as monument, affected by a direct marine and hard industrial environment from the Bilbao Commercial Harbor, the Library of the University of the Basque Country UPV/EHU, Campus of Leioa (1968), affected by the diffuse urban‐industrial atmosphere of metropolitan Bilbao. For both cases, original and decayed compounds were searched by portable Raman spectroscopy (785‐ and 532‐nm lasers) in raw materials and efflorescence salts over them. In the Galleries, the expected raw materials of Portland‐type mortars and reinforced concrete were detected, such as alite (3CaO·SiO2), belite (2CaO·SiO2), calcite (mortar and gravel) and gypsum together with quartz and aragonite, which indicates the use of beach sand as aggregate. Other compounds like nitratine (NaNO3), nitrocalcite/niter (Ca (NO3)2.6H2O/KNO3), γ‐anhidrite (CaSO4), bassanite (CaSO4·1/2H2O), mackinawite ((Fe,Ni)S), lepidocrocite (γ‐FeO (OH)), haematite (Fe2O3) and whewellite (CaC2O4·H2O) indicated also a heavy decay, because of chemical reactions between compounds in the aerosols around the building and original materials. In the Library of the UPV/EHU, apart from the same kind of original compounds, high amounts of niter (KNO3) were detected in efflorescence just underneath the upper gardens of the building, suggesting a decay due to the infiltration of ammonium nitrate charged waters. Moreover, thenardite (Na2SO4), syngenite (K2Ca(SO4)2·H2O), gypsum (in efflorescence salts), aphthitalite (K3Na(SO4)2), haematite and anatase (TiO2) were also detected in other efflorescences.