EXPERIMENTAL STUDIES ON THE EFFECT OF ADDITIVES ON CLAYEY SOIL

The present study investigates the stabilization of clayey soil using marble dust, an industrial by-product, and banana peel powder, an organic agricultural waste, to enhance soil strength and stability for geotechnical applications. Laboratory tests were carried out on natural clayey soil mixed with varying proportions of marble dust (2%, 4%, 6%, 8%, and 10%) and banana peel powder (2%, 4%, 6%, 8%, and 10%), both individually and in combination. Basic characterization included particle size distribution and specific gravity tests, followed by consistency tests (Atterberg limits) to assess the effect of additives on soil plasticity. The Standard Proctor test was performed to determine compaction characteristics, while the California Bearing Ratio (CBR) test was used to evaluate strength and load-bearing capacity. Results revealed that marble dust significantly improved the maximum dry density (MDD) and CBR values, with the highest performance recorded at a 10% replacement level (MDD = 1.795 g/cc; CBR = 9.2% at a 2.5 mm penetration). In contrast, banana peel powder reduced the liquid limit and plasticity index, improving volumetric stability but offering limited gains in CBR. The combined use of both additives showed complementary benefits, with a mix of 6% marble dust and 4% banana peel powder emerging as the optimal blend, balancing strength improvement with reduced plasticity. The findings suggest that the sustainable use of marble dust and banana peel powder not only improves soil performance but also promotes environmental sustainability through waste utilization.