Sand-Biosolids Mixture Characterization and Potential

Biosolid-sludge of sewage treatment plants was mixed with clean coarse sands to reduce soil permeability and assess the potential of utilizing such mix for several geotechnical applications. One of the applications was to develop a soil mix with low permeability for use in roadway embankments subjected to torrents from sudden heavy rain in desert areas. The main purpose was to address a sustainable and eco-friendly mix to be used as an additional protection to the current boulder lining for such embankments. In this study, biosolid sludge was mixed with medium dense sand using percentages equal to 0%, 5%, 10%, and 20% by weight of sand. The sludge was broken on sieve number 4” then a Proctor test was performed to determine the optimum moisture content to be used with all these mixes. Several other laboratory tests were conducted such as direct shear, unconfined compression and California bearing ratio to determine changes in the mechanical properties of the mixes. This in addition to the free swelling test to assess the tendency of volume expansion of these sand-biosolid mixes, as well as the constant head permeability test. © 2022, Avestia Publishing. All rights reserved.