The word “keramzit” (LECA) translated from Greek means “burnt clay”. The name itself prompts that the clay must be burnt to produce LECA. LECA is an acronym term for (Light Expanded Clay Aggregate). The essence of the process is detailed below: the prepared clay is subjected to sharp heat shocks which facilitates the provision of porosity in the material and its swelling-up. Due to the melting of the outer sheath, LECA is sealed and attains high strength.