Composition and characterisation of ancient lime mortar of Gopal Krishna temple, Alandi, India

The cementing lime mortars used in the construction of twelfth century CE Gopal Krishna temple at Western India Alandi were investigated for its mineralogical, chemical and compositional characteristics. The investigative studies were performed using particle size studies, XRF, XRD, FTIR, SEM–EDX and thermal analysis of the mortar. Though the monument is situated in Sahyadri range of Deccan basaltic trap, the mortar is marked by mixing of aggregates rich in hydrated oxides of alumina and iron. Further studies revealed natural formation of laterite capping on basaltic hillock that preferentially weathered and sediments deposited along the river basin sourced as aggregates in mortar preparation. The lime rich binder has mainly inclusion of sub-angular to sub-rounded coarse grain lateritic aggregates. The clay impurities have reduced the purity of lime as observed through thermal analysis. The data will help prepare a compatible mortar for restoration.