Normal concrete is weak against tensile strength, has low ductility, and also insignificant resistance to cracking. The addition of diverse types of fibers at specific proportions can enhance the mechanical properties as well as the durability of concrete. Discrete fiber commonly used, has many disadvantages such as balling the fiber, randomly distribution, and limitation of the Vf ratio used. Based on this vision, a new technic was discovered enhancing concrete by textile-fiber to avoid all the problems mentioned above. The main idea of this paper is the investigation of the mechanical properties of SCC, and SCM that cast with 3D AR-glass fabric having two different thicknesses (6, 10 mm), and different layers (1,2 layers). As well as micro-steel fiber with 1.25% volume fraction was used. Sixteen rectangular reinforced concrete beam specimens have been tested to study the behavior of their flexural strength. The results concluded that utilizing 3D-TFs with mortar mixture gave significantly higher enhancement for the load-carrying capacity than the concrete mixture. The utilization of 3D-TFs and micro-steel fiber together in the SCM mix gave better results. The stiffness of the specimens was improved with increasing the thickness and the number of textile fiber layers.
This study offers the elastic response of the variable thickness functionally graded (FG) by single walled carbon nanotubes reinforced composite (CNTRC) moderately thick cylindrical panels under rotating and transverse mechanical loadings. It’s considered that, three kinds of distributions of carbon nanotubes which are uniaxial aligned in the longitudinal direction and two functionally graded in the transverse direction of the cylindrical panels. Depending on first order shear deformation theory (FSDT), the governing equations can be derived. The partial differential equations are solved by utilizing the technique of finite element method (FEM) with a program has been built by using FORTRAN 95. The results are calculat
... Show MoreIn this work, the mass attenuation coefficient, effective atomic number and half value layer parameters were calculated for silicate (SiO2) mixed with various levels of lead oxide and iron oxide as reinforced materials. SiO2 was used with different concentrations of PbO and Fe2O3 (25, 50 and 75 weight %). The glass system was prepared by the melt-quenching method. The attenuation parameters were calculated at photon energies varying from 1keV to 100MeV using the XCOM program (version 3.1). In addition, the mass attenuation coefficient and half value layer parameters for selected glass samples were experimentally determined at photon energies 0.662 and 1.28 MeV emitted from radioactive sources 137Cs and 22Na respe
... Show MoreIn this paper, an exact stiffness matrix and fixed-end load vector for nonprismatic beams having parabolic varying depth are derived. The principle of strain energy is used in the derivation of the stiffness matrix.
The effect of both shear deformation and the coupling between axial force and the bending moment are considered in the derivation of stiffness matrix. The fixed-end load vector for elements under uniformly distributed or concentrated loads is also derived. The correctness of the derived matrices is verified by numerical examples. It is found that the coupling effect between axial force and bending moment is significant for elements having axial end restraint. It was found that the decrease in bending moment was
in the
The article emphasizes that 3D stochastic positive linear system with delays is asymptotically stable and depends on the sum of the system matrices and at the same time independent on the values and numbers of the delays. Moreover, the asymptotic stability test of this system with delays can be abridged to the check of its corresponding 2D stochastic positive linear systems without delays. Many theorems were applied to prove that asymptotic stability for 3D stochastic positive linear systems with delays are equivalent to 2D stochastic positive linear systems without delays. The efficiency of the given methods is illustrated on some numerical examples. HIGHLIGHTS Various theorems were applied to prove the asymptoti
... Show MoreOver the last few decades, fiber reinforced polymer (FRP) has been increasingly used in strengthening different structural concrete members. The main objective of this research is to study the influence of curvature on the performance of curved soffit reinforced concrete (RC) bridge girders that have been strengthened with carbon fiber reinforced polymers (CFRP). This experimental program was designed to evaluate the effect of concavity and soffit curvature on the CFRP laminate utilization and load capacity, compared to flat soffit RC beams strengthened with the same CFRP system. Accordingly, five beams, 2.7 m in length and having the same degree of soffit curvature (20 mm per 1 meter
Over the last few decades, fiber reinforced polymer (FRP) has been increasingly used in strengthening different structural concrete members. The main objective of this research is to study the influence of curvature on the performance of curved soffit reinforced concrete (RC) bridge girders that have been strengthened with carbon fiber reinforced polymers (CFRP). This experimental program was designed to evaluate the effect of concavity and soffit curvature on the CFRP laminate utilization and load capacity, compared to flat soffit RC beams strengthened with the same CFRP system. Accordingly, five beams, 2.7 m in length and having the same degree of soffit curvature (20 mm per 1 meter
This paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance be
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