A long-span Prestressed Concrete Hunched Beam with Multi-Quadrilateral Opening has been developed as an alternative to steel structural elements. An experimental program was created and evaluated utilizing a single mid-span monotonic static load on simply supported beams, which included six beams with openings and the solid control beam without openings, to investigate the performance of such beams. The number and height of the quadrilateral openings are the variables to consider. According to test results, the presence of openings in the prestressed concrete hunched beam with multi-quadrilateral opening did not considerably affect their ultimate load capacity with respect to a control beam (solid); the diminishing ratio of maximum strength capacity varied from 4.22 % to 13.5 %.
Exposure of reinforced concrete buildings to an accidental fire may result in cracking and loss in the bearing capacity of their major components, columns, beams, and slabs. It is a challenge for structural engineers to develop efficient retrofitting techniques that enable RC slabs to restore their structural integrity, after being exposed to intense fires for a long period of time. Experimental
investigation was carried out on twenty one slab specimens made of self compacting concrete, eighteen of them are retrofitted with CFRP sheets after burning and loading till failure while three of them (which represent control specimens) are retrofitted with CFRP sheet after loading till failure without burning. All slabs had been tested in a
This investigation was undertaken to evaluate the effectiveness of using Hydrated lime as a (partial substitute) by weight of filler (lime stone powder) with five consecutive percentage namely (1.0, 1.5, 2.0, 2.5, 3.0) % by means of aggregate treatment, by introducing dry lime on dry and 2–3% Saturated surface aggregate on both wearing and binder coarse. Marshall design method, indirect tensile test and permanent deformation under repeated loading of Pneumatic repeated load system at full range of temperature (20, 40, 60) C0 were examined The study revealed that the use of 2.0% and 1.5 % of dry and wet replacement extend the pavement characteristics by improving the Marshall properties and increasing the TSR%. Finally, increase permanent
... Show MoreThis paper focuses on Load distribution factors for horizontally curved composite concrete-steel girder bridges. The finite-element analysis software“SAP2000” is used to examine the key parameters that can influence the distribution factors for horizontally curved composite steel
girders. A parametric study is conducted to study the load distribution characteristics of such bridge system due to dead loading and AASHTO truck loading using finite elements method. The key parameters considered in this study are: span-to-radius of curvature ratio, span length, number of girders, girders spacing, number of lanes, and truck loading conditions. The results have shown that the curvature is the most critical factor which plays an important
Ischemic heart disease is a major causes of heart failure. Heart failure patients have predominantly left ventricular dysfunction (systolic or diastolic dysfunction, or both). Acute heart failure is most commonly caused by reduced myocardial contractility, and increased LV stiffness. We performed echocardiography and gated SPECT with Tc99m MIBI within 263 patients and 166 normal individuals. Left ventricular end systolic volume (LVESV), left ventricular end diastolic volume (LVEDV), and left ventricular ejection fraction (LVEF) were measured. For all degrees of ischemia, there was a significant difference between ejection fraction values measured by SPECT and echo
Nowadays, most of the on-chip plasmonic single-photon sources emit an unpolarized stream of single photons that demand a subsequent polarizer stage in a practical quantum cryptography system. In this paper, we numerically demonstrated the coupling of the light emitted from a quantum emitter (QE) at 700 nm wavelength to the propagation mode supported by an on-chip hybrid plasmonic waveguide (HPW) polarization rotator. Our results proved that the light emitted is linearly polarized at 0º, 45º/−45º, and 90º with propagation lengths of 5 μm, 3.3 μm, and 3.9 μm, respectively. Moreover, high power-conversion efficiency was obtained from an applied transverse magnetic (TM) mode (0º-polarization) to a transverse electric (TE) (90º-polari
... Show Moreيسعى هذا البحث الى تقديم اطار عملي ونظري حول موضوع "تأثير الاقتصاد المنزلي في تعزيز الاداء العالي" وتم اختبار مخطط الدراسة الفرضي في القطاع التعليمي الحكومي في محافظة البصرة ,ويتضمن عدد من تشكيلات الجامعة التقنية الجنوبية. واستخدمت الاستبانة والمقابلة الشخصية كأسلوب لجمع البيانات للدراسة وكان حجم العينة114 موظف. وقد استخدمت عدد من الاساليب الاحصائية لاختبار فرضيات الدراسة. واظهرت النتائج بأن هناك تأثير ايج
... 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
... Show MoreAn 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
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