David J. White, R.J. Baker and J. van Leeuwen

Due to the minimum transportation requirements and the desirability of recycling waste material, lime sludge from water-treatment plants is a candidate for use as fill material in road construction. Using lime sludge for this purpose could present settlement, durability, and strength problems. Therefore, when considering material for use as construction fill, important engineering parameters, including stability and volume change, must be evaluated in order to ensure sound foundations for buildings and roads. The authors investigated dried lime sludge, modified with stabilizers or mixed with soil and other solid materials, as a potential fill material for road construction. Large additions of Portland cement or Class C fly ash to lime sludge generally increase strength values and produce satisfactory unconfined compressive strength results for construction fill. An important limitation of the lime sludge and the stabilized mixtures, however, was the lack of durability through freeze/thaw cycles.

Key words: durability, fill material, leaching, lime sludge, settlement, soil stabilization, strength, water treatment residuals

Land Contamination & Reclamation, 18 (4), 393-415 (2011)

DOI 10.2462/09670513.1013

© EPP Publications Ltd 2011