Degradation characteristics of the structural building material in the city of Achir

The city of Achir is a historical medieval city which is located in North Africa more precisely in the Tettri Mountains in the current Algerian commune of Kef Lakhdar (wilaya of Medea). It is known for its cultural, political role and also as an intellectual center where forensic scientists and scholars flocked, during Fatimid suzerainty. Moreover, It was the capital of Zirids government and the heart of Sanhajian power. In this study, some pathologies of the current structural site in Achir have been investigated. The main building material found to be Tuffstone, Therefore, it was experimentally tested by X-RAY Diffraction (DRX), Scanning Electron Microscopy SEM, and magnifying glass. Findings have confirmed that the construction material was Tuffstone with volcanic origin. Also, the degraded was highly caused by environmental reasons (principally rainwater, wend and biological weathering..).