Analyze the Geotechnical Properties of Aggregate in Al-Mahzam area and Evaluation of its Suitability for Using in road purposes

Abstract

This research studies the geotechnical properties of the Quaternary deposits aggregate in Al-Mahzam area in Tikrit city/Salahadin governorate. Samples are collected from three sites on the western bank of Tigris River for studying the physical, mineralogical, chemical, strength and durability properties and evaluating its suitability for sub base in road works. The results for the physical tests through the grain size distribution test show that the aggregate is well graded and suitable to use in road works as sub base for class A. Specific gravity and density tests were carried on according to ASTM, D854,C127 Liquid limit value are (5.10, 2.2 and 4) % and the samples are non-plastic while the value of the elongation and flakiness index according to ISS, 45/1989 are (21.65, 16.04 and 15.85)% and (26.11, 28.65 and 36.00)% respectively.Mineral composition test of gravel particles revealed that carbonate gravel forming the high percentage of the mineral composition, chert and quartz, sandstone, igneous and metamorphic rocks respectively. Strength test for aggregate Impact Value were carried out according to ISS,47/1970 and B.S.812-112,1990 are (7.06,9.79 and 8.8)% which is classified to exceptionally strong which is specified that shall not exceed 30% for using in road works, and compression strength value which is derived from point load test are (197, 189.3 and 182.4) MPa. according to Hawkins classification is very strong. The durability test results represented by the loss angles test are (26.72, 26.18 and 29.55)% which is suitable for sub base road work, and the average of the soundness test results were ranges (0.62-3.54)% for coarse and fine aggregates which is within the specification and suitable to use the aggregate in roadwork as the sub base. For the chemical tests the values of organic matter, pH value, TDS and sulfate salts (gypsum %) are within the specification and suitable for using in sub base course for road.