Elemental analysis of old mortar used in various archaeological sites of Bangladesh by SEM and EDAX

Abstract

Morphological characterization and mineralogical studies were performed on fifteen mortar samples collected from three ancient archaeological sites (Wari-Bateshwar, Lalmai-Mainamati, and Paharpur) of Bangladesh. Many cracks and pores were found in the mortar samples of Buddhist Lotus temple of Wari-Bateshwar. Energy dispersive analytical x-ray analysis confirmed the presence of C, O, P, K, Al, Fe, Na, Mg, Mn, Si and Ti in the mortar samples. The absence of Ca in the samples indicates that the clay was used in the architecture as binding materials. In the clay mortar, Si played an important role and with the presence of O₂, SiO₂ was formed, which strengthened the binder. K, Al, Fe, Na, Mg, Mn, Si and Ti might form compounds like SiO₂, Fe₂O₃, K₂O, Al₂O₃, MgO, MnO, Na₂O₃, and TiO₂ with O₂. The oxidation of Fe⁺² produced Fe₂O₃ which was responsible for breaking down the bonding of mortars.

DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15595

J. Asiat. Soc. Bangladesh, Sci. 38(2): 145-153, December 2012