Qualitative assessments of Sub-base deposits of Dibdiba formation and determine their suitability for construction and engineering purposes in selected quarries at Karbala governorate/middle of Iraq

In this geotechnical study a qualitative assessment was made on the Sub-base deposits of the Dibdiba Formation from selected quarries in Karbala Governorate, central Iraq. Where 4 quarries were selected and 6 samples were taken from each quarry, bringing the total number of samples studied to 24. Physical tests such as (grain size analysis, CBR% test, Modified proctor compaction test, Atterberg limits test, and scraping ratio test) were performed, as well as chemical tests such as (sulfate content SO3%, gypsum percentage CaSO4.2H2O% test, Total soluble salts%, and organic matter% test) and the results showed that the Sub-base deposits in Dibdiba Formation in the study area falls under the class (B) according to the general specification for roads and bridges (SORB/R6,1999). The chemical tests of the studied models showed that the percentage of harmful substances is very low and that the studied Sub-base deposits are very good in terms of suitability for use for construction, engineering and road works. It is worth noting that the results of the scraping ratio test were very close, and therefore this indicates that the origin of these deposits studied is from one source.