Utilization of waste foundry sand (WFS) as impermeable layer (drainageblanket) for pavement structures

摘要

Pavement structures are susceptible to water and always been a major concern of pavementengineers. Water may enter the pavement structure from high water table and reduce the strength of granularpavement layers, causing pumping of structure under wheel loadings, resulting diminished pavement support. Inthis study waste foundry sand is considered as impermeable layer to prevent water penetration. Waste foundrysand samples were collected from different foundries operating in and around Istanbul. Index properties weredetermined. Optimum moisture contents and corresponding maximum dry densities of samples then obtainedapplying standard compaction effort. Hydraulic conductivity of samples prepared at maximum dry unit weightand optimum water content were then determined. The effects of compaction energy and bentonite content on thehydraulic conductivity were also investigated. The hydraulic conductivity values determined were in the rangebetween 1 x 10~(-5)m/s and 1 x 10~(-7)for bentonite content higher than 5%. According to the results obtained,the material may be used as drainage blanket.