Collapsible behaviour of soil is considered as one of the major problems in the stability of roadway embankment, the lack of cohesion between soil particles and its sensitivity to the change of moisture content are reasons for such problem. Creation of such cohesion may be achieved by implementation of liquid asphalt and introduction of Nano additives. In this work, silica fumes, fly ash and lime have been implemented with the aid of asphalt emulsion to improve the unconfined compressive strength of the collapsible soil. Specimens of 38 mm in diameter and 76 mm height have been prepared with various percentages of each type of Nano additive and fluid content. Specimens were subjected to unconfined compressive strength determination at dry and absorbed test conditions. It was concluded that the unconfined compressive strength increases by (13-25) folds after stabilization with asphalt emulsion at dry test condition. The implementation of lime shows that the cohesive strength is increased by a range of (93-517)% for absorbed condition, while it decreased by a range of (50- 31)% at dry test conditions. When 5% silica fumes was introduced, the compressive strength increased by 9.2% in dry test condition while it decreases in a range of (31.5-63.8)% for other percentages. When fly ash class F was introduced, the reduction in the strength was in the range of (100-120)% for various fly ash content at dry test condition.
Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt. This process uses a nonconsumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. In this investigation an attempt
has been made to understand the effect of tool pin profile and rotation diameter on microstructure and mechanical properties in aluminum alloy (2218-T72). Five different tool pin profiles (straight cylindrical, threaded cylindrical, triangular, square, and threaded cylindrical with flat), with three different rotation
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Pulsed liquid laser ablation is considered a green method for the synthesis of nanostructures because there are no byproducts formed after the ablation. In this paper, a fiber laser of wavelength 1.064 µm, peak power of 1 mJ, pulse duration of 120 ns, and repetition rate of 20 kHz, was used to produce carbon nanostructures including carbon nanospheres and carbon nanorods from the ablation of asphalt in ethanol at ablation speeds of (100, 75, 50, 10 mm/s). The morphology, composition and optical properties of the synthesized samples were studied experimentally using FESEM, HRTEM, EDS, and UV-vis spectrophotometer. Results showed that the band gap energy decreased with decreasing the ablation speed (increasing the ablation time), the mi
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Stabilization of phenol trapped by agricultural waste: a study of the influence of ambient temperature on the adsorbed phenol
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This study was aimed to determine a phytotoxicity experiment with kerosene as a model of a total petroleum hydrocarbon (TPHs) as Kerosene pollutant at different concentrations (1% and 6%) with aeration rate (0 and 1 L/min) and retention time (7, 14, 21, 28 and 42 days), was carried out in a subsurface flow system (SSF) on the Barley wetland. It was noted that greatest elimination 95.7% recorded at 1% kerosene levels and aeration rate 1L / min after a period of 42 days of exposure; whereas it was 47% in the control test without plants. Furthermore, the percent of elimination efficiencies of hydrocarbons from the soil was ranged between 34.155%-95.7% for all TPHs (Kerosene) concentrations at aeration rate (0 and 1 L/min). The Barley c
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An evaluation for the performance of model pile embedded in expansive soil was investigated. An extensive testing program was planned to achieve the purpose of this research. Therefore, special manufactured system was prepared for studying the behavior of model pile having different length to diameter ratios (L/D). Two types of piles were used in this research, straight shaft and under reamed piles. The effect of model pile type, L/D ratio and number of wetting drying cycles were studied. It is observed that significant reductions in pile movement when under reamed piles were considered. A proposed design charts was presented for straight shaft and under reamed piles to estimate the length of both types of piles that is requi
... Show MoreThe contamination of soil with the wastes of oil industry products that are complex mixtures of hydrocarbons increased recently due to the large development of oil industries in Iraq. This study deals with the remediation of low permeability contaminated clayey soil by using the enhanced electrokinetic technique (EK). The contaminated soil samples obtained from Thi-Qar oil refinery plant in Al-Nassyriah city, where the byproducts of refinery plant are disposed into that site. The byproduct contaminant treated as total petroleum hydrocarbons (TPH) to avoid dealing and complexity of treating the individual minerals and compounds consisting the contaminant. The initial concentrations of TPH were (702.7, 1168, 1235) ppm in the contaminated s
... Show MoreOne of the Iraqi geotechnical problems is the presence of gypseous soils covering about (27-36) percentage of Iraq soils containing gypsum between (10-70) ratios. The main reason for soil problematic is the gypsum dissolution when these soils are inundated. However, the soluble gypsum can be leached out of the soil particles, so these problems can be led to cracking, tilting, and collapsing the related soil structure and changing the soil properties. The aim of this work is to investigate the performance of under-reamed piles as a new, improved method to reduce the moisture sensitive and the primary triggering mechanism for the volume reduction of collapsible soil, which is considered as a non-elastic deformation; this was done by c
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This paper displays the effect of uncoated and coated chopped carbon fibers with alumina Al2O3 or Tri calcium phosphate (TCP) on the impact strength of acrylic poly methyl methacrylate (PMMA) denture base resin. To improve bonding between carbon fibers and coating materials powders, the surface of carbon fibers has been treated with Para amino benzoic acid (C9H10N2O3) and poly vinyl alcohol (PVA) was also used. The morphology of the coating layers has been examined by field emission scanning electron microscope (FE-SEM). From the results, PMMA reinforced with uncoated chopped carbon fiber has high impact strength value but still have bad aesthetic. Samples prepared b
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Soil-structure frictional resistance is an important parameter in the design of many foundation systems. The soil-structure interface area is responsible for load transferring from the structure to the surrounding soil. The mobilized shaft resistance of axially loaded, long slender pile embedded in dense, dry sand is experimentally and numerically analyzed when subjected to pullout force. Experimental setup including an instrumented model pile while the finite element method is used as a numerical analysis tool. The hypoplasticity model is used to model the soil adjacent to and surrounding the pile by using ABAQUS FEA (6.17.1). The soil-structure interface behavior depends on many factors, but mainly on the interface soi
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