Rammed earth is generally a material used by a large part of the world's population for the construction of buildings, which is generally inexpensive and durable. In addition, a large number of archaeological and historical monuments were built with this material. In Morocco, rammed earth buildings are mainly found in rural areas, where about 70% of houses are made of adobe and rammed earth, while in urban areas, this percentage is about 25%, classified as historical heritage. However, this material has limited mechanical resistance, and its degradation is accelerated in unfavorable environmental conditions. Therefore, the aim of this work is to study the reinforcement and improvement of the physical and mechanical properties of rammed earth by incorporating plastic waste such as polyethylene terephthalate polymer (PET). Several tests were executed, varying the percentage of plastic residue (polyethylene terephthalate polymer) up to 20%, in order to determine the impact of this residue on the flexural and compressive strength. The experimental findings indicate that the compressive strength can be improved by up to 70%, and the flexural strength can be improved by up to 30% with a proportion of 10% of residues.