At a specific construction site, soil excavated from a borrow site and used as a fill. The borrow site water content is 26% and the solids specific gravity is 2.65. Standard Proctor Compaction tests resulted in a maximum dry unit weight of 105 pcf at optimum moisture content of 20%. Contract specifications require 95% relative compaction. However, at the site, the contractor complains that the fill pumps and ruts badly before reaching the required dry unit weight.
a. Draw the zero air voids curve for the fill soil (use spreadsheet, i.e. excel)
b. What is the maximum possible water content at 95% relative compaction?
c. If the soil is compacted at the natural water content of 26%, what is the maximum possible dry unit weight (without pumping)?
d. Briefly explain if the contractors’ argument is valid?