To investigate the flexural behavior of self-consolidating hybrid fiber-reinforced concrete beams containing voids experimentally, six RC beams were tested, one solid without fiber and the others containing hooked-steel and macro-polypropylene fibers with a volume fraction of 1 and 0.5%, respectively. One of the five fibrous beams was solid; two contain a series of recycled plastic balls of diameters 110 and 120 mm, and another two contain a single longitudinal circular void created by PVC pipes of diameters 90 and 110 mm. The flexural behavior of the beams was assessed depending on the load-deflection curve, load-strain curve, ductility, toughness, stiffness, and crack patterns. The experimental outcomes showed that all the tested specimens (solid and voided) failed in a flexural mode. Hybrid fiber inclusion in the solid beam improved the load capacity at different loading levels, enhanced the stiffness by 38.3%, and increased the absorbed energy by 29.55%. The presence of voids in fibrous beams decreased the loads at cracking, yielding, and ultimate stages and enhanced the ductility. The ductility index, depending on deflection and energy methods, showed higher values for voided beams. The toughness of voided beams at the ultimate stage was enhanced by 1.1% to 28%. The voided beams exhibited lower values of stiffness, and their values decreased when the diameter of the voids increased. The outcomes also indicated that the incorporation of hybrid fiber significantly minimized the strain in steel reinforcing bars at the post-cracking stage, and the presence of voids minimized the reduction effect of steel strain according to void size and shape. Doi: 10.28991/CEJ-2025-011-04-08 Full Text: PDF
In this research we prepared nanofibers by electrospinning from
poly (Vinyl Alcohol) /TiO2. The spectrum of the solution (Emission)
was studied and found to be at 772 nm, several process parameters
were such as concentration of TiO2 , and the effect of distance from
nozzle tip to the grounded collector (gap distance). The result of the
lower concentration of, the smaller the diameter of nanofiber is.
Increasing the gap distance will affect nanofibers diameter
The wave functions of converted harmonic-oscillator in local scaling transformations are employed to evaluate charge distributions and elastic charge electron scattering form structures for 6,7Li, 9Be, 14,15N and 16O nuclei. The nuclear shell-model was fulfilled using Warburton-Brown psd-shell (WBP) interaction with truncation in model space. Very good agreements with the experimental data were obtained for the aforementioned quantities.
Collapse of the vapor bubble condensing in an immiscible is investigated for n-pentane and n-hexane vapors condensing in cold water and n-pentane in two different compositions of glycerin- water mixture. The rise velocity and the drag coefficient of the two-phase bubble are measured.
Inelastic longitudinal electron scattering form factors for second
excited state C42 in 42Ti nucleus have been calculated using shell
model theory. Fp shell model space with configuration (1f7/2 2p3/2
1f5/2 2p1/2) has been adopted in order to distribute the valence
particles (protons and neutrons) outside an inert core 40Ca. Modern
model space effective interactions like FPD6 and GXPF1 have been
used to generate model space vectors and harmonic oscillator wave
function as a single particle wave function. Discarder space (core
orbits + higher orbits) has been included in (core polarization effect)
as a first order correction in microscopic theory to measure the
interested multipole form factors via the model
Soil pH is one of the main factors to consider before undertaking any agricultural operation. Methods for measuring soil pH vary, but all traditional methods require time, effort, and expertise. This study aimed to determine, predict, and map the spatial distribution of soil pH based on data taken from 50 sites using the Kriging geostatistical tool in ArcGIS as a first step. In the second step, the Support Vector Machines (SVM) machine learning algorithm was used to predict the soil pH based on the CIE-L*a*b values taken from the optical fiber sensor. The standard deviation of the soil pH values was 0.42, which indicates a more reliable measurement and the data distribution is normal.
Background: Failure of resin bases were a major disadvantage recorded in the constructed dentures. Reinforcements of the repair joint with nano fillers represent an attempt to enhance the strength and durability. The purpose of the research was to estimate the influence of nano fillers reinforcement with (ZrO2 and Al2O3) on impact and transverse strength of denture bases repaired with either cold or hot processing acrylic resin. Materials and methods: A hundred and forty (140) samples were processed with hot cured resin and organized in subgroups depending on the repair materials and condition (without repair (control), repair with hot cure, cold cure, hot and cold cure reinforced with either (5% Zr2O or 0.5% Al2O3). The samples in these
... Show MoreFiber optics technology has shown immense applications in the areas of medicine, telecommunication, and imaging. For these particular applications, it requires fibers with precise cleaving. In this paper, we will demonstrate a quick, simple and efficient cleaving method that can result in a high-quality fiber surface that works well for many fiber-optic applications. The smooth tip and good surface quality obtained on the cleaved surface of optical fiber is demonstrated by using a microscope imaging system and was flat surface with a 900 angle for perpendicular cleavages. The precision cleaver provides smooth and high-quality cleaves on single-fiber surfaces as opposed to the ruby scribe pen. The defects that may occur during the cleaving p
... Show MoreRecently, the application of geosynthetics in the reinforcement of weak subgrade is expanded dramatically. However, selection of the geo-material that fits site conditions and soil type is crucial to achieving the success of the overall performance of such improvement. Also, the road life and cost construction are significant keys for evaluating this type of ground treatment. This paper presents an overview of the subgrade strengthening with geosynthetics to acquire a better understanding of the technique and to provide a clear guide for transportation and geotechnical engineers. The rutting failure along with its main causes are highlighted briefly. The types of geosynthetics, their applications and
This study aimed to investigate the influence of longitudinal steel embedded tubes located at the center of the column cross-section on the behavior of reinforced concrete (RC) columns. The experimental program consisted of 8 testing pin-ended square sectional columns of 150×150 mm, having a total height of 1400 mm, subjected to eccentric load. The considered variables were the steel square tube sizes of 25, 51 and 68 mm side dimensions and the load eccentricity (50 and 150) mm. RC columns were concealed steel tubes with hollow ratios of 3%, 12% and 20% depending on tube sizes used. The experimental results indicated an improvement in the overall behavior of eccentric columns when steel embedded tubes are used. The maximum gain in
... Show More