Abstract Dispersive clays pose significant geotechnical challenges due to low strength, poor stiffness, and high erosion susceptibility. This study investigates the mechanical, dynamic, and dispersive responses of an artificially prepared dispersive clay stabilized with cement (CE) and polypropylene fibers (PPF), applied individually and in combination, using unconfined compressive strength (UCS), bender element (BE) test, pinhole, and disintegration tests. Cement was the primary stabilizing agent, inducing substantial microstructural bonding through hydration reactions. At 8% cement content (CE) after 56 days, UCS and Vs reached 1,474 kPa and 289.6 m/s, representing increases of about 1743% and 375% over the untreated soil (80 kPa and 61 m/s), and satisfying Eurocode 7 requirements. Hydraulic tests confirmed a transition from highly dispersive (D1) to non-dispersive behavior (ND1–ND2), with zero mass loss observed at 8% CE. PPF provided mechanical reinforcement only, increasing UCS by up to 152% at a fiber content of 0.6%, which produced the most favorable response among the tested PPF contents, but remained ineffective in improving stiffness (Vs < 200 m/s) or erosion resistance when used alone. The combined treatment (8% CE + 0.6% PPF) achieved a peak UCS of 1,750 kPa, representing an increase of approximately 18.7% compared to the cement-treated soil (1,474 kPa), while Vs and Gₘₐₓ decreased by about 18.9% and 35.6%, respectively, relative to cement-only values (289.6 m/s and 149 MPa), while reducing disintegration losses to 0.5%. These findings indicate that cement provides chemical stabilization, while fiber inclusion improves post-bonding durability and crack resistance, enhancing strength but reducing small-strain stiffness due to its flexible nature.
Ahmed et al. (Fri,) studied this question.