Subgrade Improvement with the Addition of Molten Polyethylene Bags in Clay Soils

This research analyzes the improvement of clay soil subgrades by adding recycled molten polyethylene bags, offering a technical and ecological option for the construction of urban roads in Huancayo, Peru, where clay soils often weaken road structures. We will stabilize and improve their resistance using molten polyethylene bags as a stabilizer and measure their effect on soil resistance, in accordance with current standards. We analyzed three types of soil, verifying their physical and mechanical properties with methods such as Particle Size Distribution (PSD), Atterberg Limits, USCS and AASHTO classification, Modified Proctor Test(MPT) and California Bearing Capacity (CBR) test, and then incorporated molten polyethylene bags in proportions of 0.5%, 1.0% and 1.5% to observe the behavior of the soil at 95% and 100% of its maximum dry density. The results showed that the gradual addition of plastic increased the CBR index for soils with less than 60% fines and a plasticity between 14% and 17%, and that with a compaction of 95% and a dosage of 1.5%, the CBR reached approximately 6.71%, representing an improvement of around 15% compared to the untreated soil. However, in soils with more than 70% fines, where clay predominates, the improvement was minimal and did not meet the minimum standards. These results contribute to establishing technical guidelines for the use of this additive in urban road projects.