Abstract
Sand dunes cover an area of 16.6% of the total area of Egypt. This paper presents the results of an extensive laboratory testing that was carried out to determine the engineering properties of concrete. The concrete fine aggregate is fine dune sands obtained from three sites in the Kharga Oasis, Western Desert, Egypt. All samples were classified as poorly graded sand according to the Unified Soil Classification system. Fineness modulus values of the studied dune sands range from 0.89 to 0.97. The percentage of sulfates and chlorides are very low and nearly negligible. Sodium and calcium hydroxides were recorded in some samples with scarce concentration. Organic impurities were not recorded. The degree of workability of the studied dune sands ranged from low to medium, which are suitable for normal reinforced work without vibration and heavily reinforced section with vibration. The measured compressive strength of concrete decreases with increasing dune sand content.