An Investigation into the Characterization of mortar in a historical structure called Soqāya of Rab’-e Rashidi Complex in Tabriz

The Rab’-e Rashidi Complex in Tabriz, which was built in 1300 AD, it has been used in various military and residential forms until the 17th century AD. One of the architectural structures of Rab’-e Rashidi is a Hydraulic structure hypohesized as the Soqāya, which is located on the southeastern front. Archaeological excavation of Rab’-e Rashidi Soqāya site was began in 2007 by the cultural heritage deputy of Tabriz. But during this period, technical study on mortar (wall-mounted mortar and plastered mortar) in this part of Rab’-e Rashidi Complex has not been done. Technical studies on the materials of this Hydraulic structure (the present study is part of these studies), can lead to the recognition of the identity and use of the building in the future. Therefore, the mortar technology used in this Hydraulic structure requires recognition by scientific methods including field and laboratory studies and analytical and experimental. In this regard, samples were taken from three coated layers as well as brick mortar and XRD, XRF and SEM-EDS studies were performed. As a result of studies, it was found that the brick mortar and mortar of the coated layers are Lime Mortars. In the processing stage, some sand and soil are added to all mortars, with the difference that the amount of soil and sand in the brick mortar is much higher and therefore, its quality is lower than the coated mortar. Also, a small amount of charcoal powder was detected in the mortar of the coated layers.