Improving some of geo technical properties of an organic soil using crushed waste concrete

Many urban areas are now struggling with the high volume of solid wastes, especially the construction and demolition materials. In this study, the crushed waste concrete (CWC), which is considered as one of the biggest components of solid waste, was used to improve some geotechnical properties of an organic soil. The CWC at the ratios of 5%, 10%, 15%, and 20% were added to organic soil in order to conduct an intensive series of experimental tests. The laboratory tests included the consistency limits by fall cone, modified compaction, unconfined compressive strength (UCS), and swelling percentage. The results show that when the CWC percentages were increased to 50%, there were decreases of about 30% and 60% in liquid limit and plasticity index of clay, respectively. Increase of about 35% in γdrymax for the organic soil was noticed when the CWC content was increased from 10% to 50%. A reduction of about 50% of wopt for organic soil was shown by increasing the CWC percentage to 50%. The UCS values of the organic silt increases by around 25% by increasing the CWC percentage up to 50%. The swelling percentage increased by adding CWC up to 30%, and then decreased with the addition of CWC up to 50%.and increasing the CWC proportions has a positive effect on the consolidation features of organic soil. CWC decreased the consolidation of organic soil by decreasing the compression index (Cc) and the time of consolidation for organic soil was decreased due to the increasing of the coefficient of consolidation (Cv) and coefficient of conductivity (k) for organic-CWC mixtures