الملخص الإنجليزي
The Arabic term "Sabkha" refers to salt-encrusted plains that lie beneath sand, silt or clay
soil. Sabkha is distributed in many areas in Oman, such as the coast of Batina, Ash
Sharqyah, Al Wusta and Ad Dhahirah, Umm Samim and Barr Al-Hikman. Owing to the
high salt content level of sabkha soil, geotechnical problems appear, including low shear
strength, primary and secondary settlement, corrosion, crystallized salt heaving, and flood
problems for low rates of infiltration.
This research aimes to investigate the use of marble waste powder for stabilizing Sabkha
soils. The samples of sabkha soil (SB) were collected from Al-Azaiba-Muscat, Sultanate
of Oman. An experimental program has been performed to identify the essential
characteristics of the collected soil, along with its physical, geotechnical, and chemical
properties. Soil samples were treated with cement (C) as a control binder and with cement marble waste (MPC) mix at ratios 0/100, 20/80 and 40/60%. Binders were supplemental
to the soil at proportions of 0, 2.5, 5, 7.5, and 10% by dry weight. In addition to physical
and chemical properties, unconfined compressive strength (UCS), California Bearing
Ratio (CBR) , Scanning Electron Microscope (SEM) , Energy Dispersive Spectroscopy
(EDS) , and X-Ray Fluorescence (XRF) were conducted for all treated samples.
The main findings indicate that the UCS and CBR of treated sabkha with 20% waste
marble powder is higher than sabkha treated with cement. This, due to the good properties
of cementitious materials and microfiller of waste marble powder.
In addition, According with the Unified Facilities Criteria (Department of Defense USA,
2004), the Federal Highway Administration (FHWA) (2013), the Mechanistic-Empirical
Pavement Design Guide (MEPDG, 2004), and the Indian Road Congress, New Delhi (IRC
37, 2012), sabkha treated by 5% of binder that contained 20% waste marble powder, could
be used as a subgrade course and subase layers. According to the Texas Department of
Transportation (2019) and the Portland Cement Association (1992), sabkha treated by 5%
of binder that contained 40% waste marble powder could be used for cement-treated sub base layer.
According to the Omani Highway Design Standard, all treated sabkha can be used for
embankment. Also, sabkha treated by 5% of binder that contained 40% and 20% waste
marble powder, treated sabkha with 7.5% of binder that contained 40% and 20% waste
marble powder and treated sabkha with 10% of binder that contained 40% and 20% waste
marble powder can be used for a drainage layers. Moreover, 5% of binder that contained
20% waste marble powder and 10% of binder that contained 40% and 20% waste marble
powder can be used for subbase.
