Study of Clay Soils, Case of Dibang - Cameroon: Thermophysical and Chemical-Mechanical Characterization of Clay Bricks Loaded with 7% of Polyethylene Aggregates

The work presented in this article demonstrates that mixing clay from clay soils with polyethylene aggregates is possible for the production of stabilized earth bricks. We manufactured raw stabilized clay bricks, which we fired at 900°C with 0% and 7% polyethylene aggregate content. We characterized them physically, chemically, thermally, and mechanically using standard norms and equipment. Our physical characterization showed that the density of the material decreases when loaded with 7% polyethylene aggregates and, conversely, our mechanical characterization showed that compressive strength decreases in the raw state and increases in the fired state with the addition of the load. Thermal characterization (ATG, DSC, and DTG) shows that the mixture with 7% polyethylene aggregates contains free water, kaolinite, illite, and quartz with a high silt content, indicating the presence of both clay and polyethylene aggregates. Chemical characterization (FTIR) shows that the clay + polyethylene aggregate mixture has the presence of an intense peak at 1002.72 cm-1 and a band at 757 cm-1 relating to the elongation and torsion vibrations of the Si-O bonds respectively for the loaded and unloaded raw bricks. The bands at 1877.71 and 2850.07 cm-1 correspond respectively to the stretching vibrations of the Si-O-Si and Si-O-Al bonds and can be attributed to the -C-O groups of alcohols and esters. In addition, we have an intensity band between 785.20 and 943.86 cm⁻¹ that can be attributed to the -O-H groups of alcohols, allowing us to observe the influence or presence of polyethylene in the mixture when heated to 900°C.