Combined Stabilization of Clay Using Lime and PVC Fibers

<p>Reinforcing soil for foundations or embankments is crucial for ensuring structural stability and longevity. Many methods are used in Geotechnics to reinforce soils, which can be broadly categorized into chemical processes and mechanical approaches. Furthermore, reinforcing soils with fibres is an effective technique in geotechnical engineering to enhance the mechanical properties of soils, such as their strength, stiffness, and resistance to deformation. Despite significant research in this area, the stabilization of clay soils remains a dynamic and evolving field, with ongoing efforts to explore innovative materials, advanced techniques, and sustainable practices to address the challenges associated with problematic soils in construction and infrastructure development. This research aims to improve the geotechnical characteristics of very plastic clay by a combined stabilization: lime treatment at a minimum dosage and reinforcement with PVC (polyvinyl chloride )-type plastic fibres of different sizes from industrial waste. The study involves a comprehensive approach to soil stabilization by first characterizing the reference clay material, then enhancing its properties through lime pre-treatment and reinforcement with plastic waste, followed by assessing the geotechnical properties through various tests: bearing capacity, compressibility and direct shear tests. As a result, Californian Bearing Ratio (CBR)  immersion tests revealed that mixtures of treated clay and PVC fibres achieve acceptable bearing capacity under low and medium compaction energies without requiring intense compaction. Furthermore, Unconsolidated undrained shear tests highlighted the short-term behavioural improvements from combining lime treatment with PVC fibres, while œdometric tests demonstrated their positive impact on the swelling and compression of plastic clays. Through this experimental study, it can be concluded that the treatment of clay with lime at minimum dosage and the reinforcement of its structure with the addition of PVC waste is an interesting technical solution for the improvement of clay soil behaviour.</p>