Stabilization of Weak Dredged Soils by Employing Waste Boulder Crusher Dust: A Laboratory Study

Dredged soils are weak soil deposits generated by dredging of water bodies. Construction of engineering structures on weak soils is considered unsafe and hence it becomes essential to utilize such deposits to reduce the load on engineers in finding alternative sites. In this study, a waste material produced post crushing of boulders in crushing units being left in huge quantities and posing enormous environmental, health as well as disposal problems was chosen as an additive for stabilization. Boulder dust being a natural waste has no harmful constituents or chemicals present in it, making it a sustainable product. The mechanical properties of the treated soil were studied by adding boulder crusher dust (BCD) in increments of 4%. Consistency limits, compaction characteristics, California bearing ratio and unconfined compressive strength were studied. Curing period of 7 and 21 days was given to the UCS samples in order to determine the effect of bonding due to possible cementitious material formations. The strength at 16% BCD and 21 days curing increased from 46 kN/m² in the untreated state to 192 kN/m². The experimental results were further supported by micro structural analysis indicating that the BCD is a promising additive for stabilization of the dredged soils and hence, can be used in various engineering applications like sub grade, backfill material, landfills, embankments etc. without affecting the ecology of the site and restoring the damages done by the waste material.