Thermal, mineralogical and chemical studies of the mortars used in the cathedral of Pamplona (Spain)

Different ancient mortar samples of Pamplona cathedral have been analysed to characterize their binder and aggregate fractions. A complete characterization has been carried out including chemical (complete macrochemical analysis, analysis of the soluble fraction in hot HCl (1:5) and of the insoluble residue, trace elements and soluble salts, using traditional chemical procedures, ion chromatography and spectrophotometry techniques), mineralogical (structural characterization, granulometric studies and X-ray diffraction) and thermal studies (simultaneous DTA and TG analysis). A lime binder with a silica aggregate has been established. The approximate original compositions of the classes of mortars have been determined using the TG results. A good agreement with the other characterization techniques has been showed by the thermoanalytical techniques. An incomplete carbonation in a sample has been discovered by the thermal analysis.