الفهرس 
Collapsible soilsOnly 14 pages are availabe for public view
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Abstract
Cost effective construction techniques, such as reusing waste materials play important role in dramatically reducing costs. In recent years, sludges have gained considerable attention as a geotechnical material. The increase in the demand of drinking water from purification plants produces a huge amount of water treatment residuals (WTR). The disposal of such residues can be considered problematic issue.In this study, innovate and economic method to disposal WTR was presented. Comprehensive experimental investigations have been done to determine the effect of utilizing WTR as a substitution layer in collapsible soil through roads construction processes. The investigations extended to the geotechnical and spectroscopic properties. Tests were carried out on the soil sample mixing with different percentages of WTR. The geotechnical measurements include particle size distribution (PSD), single oedometer test (SOT), modified Proctor test and the California bearing ratio (CBR). The samples morphology and composition are characterized by scanning electron microscope (SEM) and the energy dispersive spectroscope analyzer (EDS). The microstructure and organic constituents are analyzed by x-ray diffraction (XRD) and the Fourier transform infrared (FTIR). from the geotechnical point of view, WTR can be safely deposed by mixing with collapsible soil as a subgrade of road construction up to a value of 10 % without any impact or reduction on CBR values. Moreover, the results illustrate the remarkable improvement in the collapse potential of the soil, which is reduced by IIIabout 24.7% by mixing it with 10% WTR. The microstructure analysis confirms that WTR acted as a pore filler to decrease the porosity and create a denser and solidified structure which reduces the suction and maximum collapse potential. Mineralogical analyses implied that the soil with WTR turns into a rich medium with metal cations and organic matters that react with minerals to form binding materials.