Strength and Consolidation Characteristics of Compacted Clayey Soil Having a Special Case of Standard Compaction Curve

This paper deals with the results of an experimental study carried out on compacted clayey soil, to investigate the strength and consolidation characteristics of this soil. This soil having special case of standard compaction curve contain two values of maximum dry unit weight and two values of optimum moisture content between these point minimum dry unit weight was occurred.The results show that the maximum compressive and tensile strength lies on point near the point of second peak on standard compaction curve. Also the maximum bearing capacity and minimum settlement at the same point on standards compaction curve. Finally the preferred zone to conducted the compaction in field at this point where the dry unit weight at this point was 16.5kN/m3 while the moisture content was 18%

Effect of Fibers on Some Engineering Properties of Cement and Lime Stabilized Soils

Recently, many attempts were made to use metal fiber reinforcements to improve some soil properties. In this research, the effects of fibers on the compaction and mechanical properties of cement and lime stabilized soils (silty and clayey soils respectively) were studied. Variables such as stabilizer (cement and lime) content, amount and type of metal fibers were studied. Results indicated that the addition of fibers lead to increase in the maximum dry unit weight. On the other hand, a maximum values of unconfined and tensile strength were obtained with the addition of 0.5 % short fiber (FS) and 1.5 % long fiber (FL) respectively. During the flexural test a brittle manner failure was observed for the unreinforced samples and samples prepared with little amount of fibers 0.5%. Finally, the addition of fibers increases the fracture energy of cement stabilized silty soil and lime stabilized clayey soil

Long Term Strength and Durability of Clayey Soil Stabilized With Lime

This study deals with durability characteristics and unconfined compressive strength of clayey soil stabilized with lime. The tests comprises of unconfined compressive strength for samples stabilized with the optimum lime percent (4%), and subjected to cycles of the wet-dry, dry-wet and freeze-thaw durability tests as well as, long-term soaking and slake tests. The results indicated that, the efficiency of the lime in the improvement of unconfined compressive strength of clayey soil is of negative effect in the long term durability periods The wetting-drying cycles showed greater reduction in unconfined compressive strength than drying-wetting cycles, while the volume change of samples which subjected to drying at first, was greater than those conducted with wetting. On the other hand, freezing-thawing cycles causes a decreasing in the unconfined compressive strength values, and the reduction ratio was greater than wetting and drying cases. But, during soaking tests it was found that at early soaking periods, the lime stabilized samples continuously gaining strength, but beyond this the strength decreased with increasing soaking period. Finally, the stabilized samples with (4 and 6%) lime becomes more durable against the cycles of wetting and drying

Effect of high-pressure torsion on microstructure, mechanical properties and corrosion resistance of cast pure Mg

© 2018, The Author(s). High-pressure torsion (HPT) processing was applied to cast pure magnesium, and the effects of the deformation on the microstructure, hardness, tensile properties and corrosion resistance were evaluated. The microstructures of the processed samples were examined by electron backscatter diffraction, and the mechanical properties were determined by Vickers hardness and tensile testing. The corrosion resistance was studied using electrochemical impedance spectroscopy in a 3.5% NaCl solution. The results show that HPT processing effectively refines the grain size of Mg from millimeters in the cast structure to a few micrometers after processing and also creates a basal texture on the surface. It was found that one or five turns of HPT produced no significant difference in the grain size of the processed Mg and the hardness was a maximum after one turn due to recovery in some grains. Measurements showed that the yield strength of the cast Mg increased by about seven times whereas the corrosion resistance was not significantly affected by the HPT processing

Design, construction and calibration of an instrument for measuring the production of chilled water by the combined effects of evaporation and night sky radiation

This paper presents the design and mathematical modeling of thermal radiator panels to be used primarily to measure night sky radiation from dry and wet coated surfaces. Three panels may be used in conjunction as a combined measuring system. One panel consists of an upper dry surface coated aluminum sheet laminated to an ethylene vinyl acetate foam backing block having a pattern of parallel flow water channels and header channels milled into its mating surface prior to lamination to the aluminum sheet. This configuration provides a fin and channel radiator instrument whereby circulating water may be used to measure the heat loss from this panel to night sky radiation. In a second configuration, the surface of a panel without buried water channels but otherwise identical may be wetted in order to study and compare the night sky radiation from its wet surface. In this case, the measuring water is circulated over the upper face of this panel. In a third configuration, water is sprayed onto the surface of the second panel (or a similar panel) so that an evaporative cooling effect is gained in addition to the radiation effect. Initial TRNSYS simulations for the performance of all three configurations are presented and it is planned to use the panels as calibrated instruments for discriminating between the cooling effects of night sky radiation and evaporation. Copyright © 2012 by ASME