Abstract
Small quantities of Roman mortars and stuccos from the Theatre of Marcellus and Porticus of Octavia were subjected to different instrumental techniques - thermogravimetric analysis (TG, DTG), Inductively Coupled Plasma Emission Spectroscopy (ICP-AES) and X-ray diffraction (XRD). The instrumental characterisation and chemometries allowed the stucco samples to be easily distinguished from the mortar. In practice, using the three instrumental analytical methods a total of 36 variables were obtained. The variables were then selected using PCA (Principal Component Analysis), reducing this number to 10. Lastly, using HCA (Hierarchical Cluster Analysis) a good separation was obtained between the two groups of samples (mortars and stuccos).
Keywords: PCA, HCA, Thermogravimetric analysis, XRD, Old Roman mortar and stucco