For design purposes, it`s necessary to know the compression rate of soil layers which might be happened when it`s subjected to effective stresses. Also, it`s essential to know the rate of flow through soil mass specially for the design of marine structures or earth embankment. These two important behavior could be predicted from the coefficient of consolidation (Cv) and the coefficient of permeability (k). This study shows the effect of cutback asphalt stabilization on Cv and k and other compressibility factors, the investigation was done for silty clay samples, specimens were prepared by mixing the soil with different percentage of asphalt from (0-10)% and subjected to one-dimensional consolidation test of 50mm diameter and 20mm height were done at soaked condition, it was conducted that Cv increased for asphaltic soil of (2-6)% Cutback and decreased for soil with cutback of (8-10)%. On the other hand, the the coefficient of permeability (k) and the coefficient of volume change (mv) increased for soil with (2-4)% cutback and decreased by adding more cutback asphalt to soil till 10%. The compression index (Cc) value increase to the optimum value at 2% cutback content then start to decrease till reaching the 10%. The re-compression index (Cr) shows a general increase in values when add cutback asphalt to the soil, it increase until reaching its maximum value at 6% cutback content then decrease with increasing of cutback asphalt till 10%, the values of (Cr) shows an increase for the 10% cutback from 8%, that’s might be due to increasing of swelling potential due to increasing of liquid limit and blocking of voids ratio.
Due to increasing cost of asphalt binder, significant economic savings can be realized by using the amount from reclaimed asphalt pavement (RAP) in the production of new hot mix asphalt (HMA). Moreover, this is an environmentally friendly option as it reduces the demand for virgin materials. It has to be remarked that in Iraq RAP is not used in the production of HMA and this valuable material is mostly degraded for use in lower value applications. Four mixtures were designed, which contains three different percent RAP, it is (0%, 5%, 15%) with asphalt grade (40-50) and (25%) with asphalt grade (60-70), it has been changed the grade of asphalt when adding RAP (25%) to compensate for the aged binder in the RAP when adding to mixture. All type
... Show MoreIn the lifetime process in some systems, most data cannot belong to one single population. In fact, it can represent several subpopulations. In such a case, the known distribution cannot be used to model data. Instead, a mixture of distribution is used to modulate the data and classify them into several subgroups. The mixture of Rayleigh distribution is best to be used with the lifetime process. This paper aims to infer model parameters by the expectation-maximization (EM) algorithm through the maximum likelihood function. The technique is applied to simulated data by following several scenarios. The accuracy of estimation has been examined by the average mean square error (AMSE) and the average classification success rate (ACSR). T
... Show MoreNonlinear diffraction pattern can be induced by focusing CW
laser into a thin quartzes cuvette containing nanofluid. The number
of revealed pattern rings indicates to the nonlinear behavior of fluid.
Here, the nonlinear refractive index of each of functionalized single
wall carbon nanotube (F-SWCNTs) suspention and multi wall carbon
nanotube (F-MWCNTs) suspention have been investigated
experimentally .Each of CNTs suspention was at volume fraction of
13×10−5 and 6×10−5. Moreover the laser source at wavelength of
473 nm was used. The results show that SWCNTs suspention
possesses higher nonlinearty than other at the same volume fraction
In this paper, mesoscale modeling is performed to simulate and understand fracture behavior of two concrete composites: cement and asphalt concrete using disk-shaped compact tension (DCT) tests. Mesoscale models are used as alternative to macroscale models to obtain better realistic behavior of composite and heterogeneous materials such as cement and asphalt concrete. In mesoscale models, aggregate and matrix are represented as distinct materials and each material has its characteristic properties. Disk-shaped compact tension test is used to obtain tensile strength and fracture energy of materials. This test can be used as a better alternative to other tests such as three points bending tests because it is more convenient for both field and
... Show MoreThis study designed to prepare ultrafine apixaban (APX) o/w nanoemulsion (NE) based gel with droplet size below 50 nm as a good method for transdermal APX delivery without using permeation enhancer, alternatively, the formulation components itself act as permeation enhancer. APX, a potent oral anticoagulant drug that selectively and directly inhibit coagulation factor Xa, was selected as a good candidate for transdermal delivery as it displays poor water solubility (0.028 mg/mL) and low bioavailability (50%). APX-NE gel was prepared using triacetin, triton-x-100 and carbitol as oil phase, surfactant and cosurfactant respectively, while Carbopol 940 used as a gelling agent. Ex vivo permeation of APX-NE gel through human stratum c
... Show MoreSoil improvement has developed as a realistic solution for enhancing soil properties so that structures can be constructed to meet project engineering requirements due to the limited availability of construction land in urban centers. The jet grouting method for soil improvement is a novel geotechnical alternative for problematic soils for which conventional foundation designs cannot provide acceptable and lasting solutions. The paper's methodology was based on constructing pile models using a low-pressure injection laboratory setup built and made locally to simulate the operation of field equipment. The setup design was based on previous research that systematically conducted unconfined compression testing (U.C.Ts.). Th
... Show MoreThe present research aims to study the effect of friction stir welding (FSW) parameters on temperature distribution and tensile strength of aluminum 6061-T6. Rotational and traverse speeds used were (500,1000,1400 rpm) and (14,40,112 mm/min) respectively. Results of mechanical tests showed that using 500rpm and 14mm/min speed give the best strength. A three- dimensional fully coupled thermal-stress finite element model via ANSYS software has been developed. The Rate dependent Johnson-Cook relation was utilized for elasto-plastic work deformations. Heat-transfer is formulated using a moving heat source, and later used the transient temperature outputs from the thermal analysis to determine equivalent stresses in the welde
... Show MoreIn this study, the effect of design parameters such as pipe diameter, pipe wall thickness, pipe material and the effect of fluid velocity on the natural frequency of fluid-structure interaction in straight pipe conveying fully developed turbulent flow were investigate numerically,analytically and experimentally. Also the effect of support conditions, simply-simply and clamped-clamped was investigated. Experimentally, pipe vibrations were characterized by accelerometer mounted on the pipe wall. The natural frequencies of vibration were analyzed by using Fast Fourier Transformer (FFT). Five test sections of two different pipe diameters of 76.2
mm and 50.8 mm with two pipe thicknesses of 3.7 mm and 2.4 mm and two pipe materials,stainles