Geotechnical Behavior of Stabilized Dunes Sand by Cement

The dunes sand is wide spread with huge quantities all over the world especially in desert areas near roads. The objective of the current paper is to use dunes sand as a foundation soil under structures instead of utilizing expensive replacement with structural fills. The dunes sand samples were collected from a site outside Tabuk city in the north-west of Saudi Arabia. Several experimental tests were performed on the dunes sand samples such as sieve analysis, standard Proctor compaction, drained direct shear and CBR. The test results indicated that the sand dunes are SP according to USCS. The sand dunes have also low shear strength and CBR value. The bearing ability of the sand dunes became weaker due to water immersion. Therefore, the construction on the non-treated dunes sand is impossible. For the later reason, the dunes sand was stabilized with various ordinary Portland cement fractions ranging from 3% to 15%. Compaction and CBR tests were conducted on the stabilized dunes sand. The maximum dry density increased as the increments of the cement contents accompanying with the decrement of porosity and optimum moisture content. The stabilized dunes sand implied higher CBR values than the non-treated soil.  The CBR values of the stabilized soil increased with increasing cement fractions. The stabilized dunes sand induced very high CBR values after longer curing times for all the utilized cement contents. The stabilized dunes sand using only 3% is considered the optimum design achieving good performance under structures and best economic mix