Stabilization of sebkha soil using foamed asphalt

In recent years, considerable research has been conducted in the construction of pavement layers incorporating foamed asphalt (FA). Development of improved foaming techniques has enabled both effective and economical stabilization of marginal quality pavement materials. This paper explores the ability of using FA to stabilize local sebkha soils to be used as a base or subbase material in asphalt structures under the relatively high temperature conditions in eastern Saudi Arabia. For the sake of relative performance and cost comparison, three types of treatment were used to stabilize the low quality sebkha soil: FA, emulsified asphalt, and sulfate-resisting (type V) portland cement. Marshall stability, indirect tensile, and unconfined compressive strength tests were performed to evaluate the properties of Marshall-prepared samples. Properly designed FA sebkha soil with as little as 2% cement displayed significant improvement in the strength properties, as compared with those of emulsified and cement-treated sebkha mixes. From cost perspectives, the FA-sebkha-2% cement mixture exhibited a superior rating as compared with the other stabilizing agents.