The purpose of this report is to determine the effectiveness of using shear walls with Moment-resisting frames by modeling two bare frame structures. The first model is a combination of bare frames and shear walls, and the second model is without she ar walls, and analyzing them statically (LATERAL FORCE METHOD) and dynamically (RESPONSE SPECTRUM METHOD) using ETABS 2016 software, and comparing the results of base shear forces, displacements and vibration modes, in order to form a comprehensive understanding of the proper use of shear walls. The report raises critical questions regarding the key factors of resisting seismic forces on similar structures, where rigidity or ductility can play opposing roles in the overall structure resistance.
The research aims to evaluate the micro shear bond strength of the calcium silicate cement (Biodentine) and the glass ionomer cement (GIC) to dentine. The study was performed using upper or lower premolars, and samples were divided into six equal s ubgroups according to the time period (3 h, 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks), in order to study changes in the values of shear bond strength with time. The comparative study showed that the success rate of adhesion in the Biodentine group was smaller than that in the GIC group for the tested premolars after 3 hours and one day, whereas the success rate in the Biodentine group was greater than that in the GIC group for the tested premolars after 8 weeks. Results showed a positive correlation between the mean values of shear bond strengths and the studied time in Biodentine group, which ranged from 1.49 ± 0.18 MPa at 3 hours to a maximum value of 2.65 ± 0.26 MPa after 8 weeks. While there was a negative correlation between the mean values and the studied time in the GIC group and values ranged from 3.02 ± 0.13 MPa at 3 hours and 2.06 ± 0.09 MPa at 8 weeks. The study showed the advantage of Biodentine compared with GIC in terms of micro-bonding to dentine, which can have a clinically significant importance in preventing the micro leakage and reducing bacterial contamination.
The behavior of the basaltic shear diaphragms of the remaining buildings of ancient times was investigated as experimental research,and its resistance to natural factors and horizontal loads resulting from wind and earthquakes,to take advantage of them in the maintenance of modern buildings,which are associated with floors and beams as horizontal shear diaphragmsIn the hot and cold areas of the African continent, Asia and other similar areas,to replace the reinforced concrete shear diaphragms,and metal shear diaphragms that lose their resistance to the above factors. When the buildings are inspected, the vertical and slanted slits resulting from the side loads are placed,it was found that the appearance of the cracks related to the hardness of the shear diaphragm section, the basalt stone specifications and the design of the shear diaphragm base.The research was conducted to determine the durability, water permeability and resistance to pressure and tensile strength of basalt stone samples used in historic stone buildings and their location in laboratory methods.Horizontal loads resulting from seismic intensity were determined on the front of the building at the tile level according to international requirements and specifications.The method of calculating the basaltic shear diaphragms was applied by applying arithmetic to build a basalt stone from several floors and a basement, taking into account the characteristic resistance of basalt, depending on its density from pressure and stretching and basalt stone in calculating.
Structural Frame system is considers as an earthquake resisting structural systems. On the other hand, many techniques were used to improve the resistance against lateral loads. where Steel Plate Shear Wall fixed within frame span is one of those techniques. This research aims to develop the Strip model of Partial Steel Plate Shear Walls with Reinforced-Concrete Frame with opening parallel to beams.
Beams are considered as one of the most loaded concrete elements, which needs to be strengthened either as a result of insufficient of concrete section, or insufficient rebar or increased loads, or the result of a superficial steel or corrosion of internal steel reinforcement, and other reasons that we will mention them what we need to study this. The damaged structural elements and their inability to function fully as a result of exposure to different environmental factors damage materials and lead to lower resistance, or because of the existence of of an executive defects or inappropriate investment for its, leads to the need to rehabilitate maintenance and repair or reinforcement. So it was resorting to strengthen either magnify sections or supply necessary reinforcement or steel platelets linking external supported well to concrete section, and because of the difficulty of execution the recent studies has been implemented on the use of more efficient material which is concentrated fiber reinforced polymers. We will present here to methods of strengthening the shear up to the global studies conducted using these materials from polymers, which are characterized by high resistance to tensile and large resistance to environmental factors and weather conditions and ease of application in the specified permissible sites.
It was investigated in this study the influence of Carboxymethylcellolose (CMC) solution concentration, temperature, and pH on the rheological properties according to the shear stress as function of shear rate. Experimental results show that shea r stress increase at all operational conditions as the shear rate increase. When the shear rate is constant, the shear stress increases also with the increasing of both concentration and pH as well as the decreasing of temperature.
Using high strength concrete made a big step in designing and constructing reinforced concrete structures. In this research, shear resistance of high strength concrete beams with average resistance of (65Mpa) and without shear reinforcement was ca lculated by making Experimental tests, also we studied the effect of cross section shape on shear resistance, and measured the deflection in the middle of the beams then we compared these results with the mathematical results and with results from other researchers, finally we developed a relationship to determine shear capacity in high strength concrete T beams.
Many techniques have been used in repair and strengthening of reinforced beam, among which are external steel beams, external pre- stressing, epoxy injection, additional concrete overlay, external steel plates, additional longitudinal and transver se - steel bars. Fifteen R.C. beams were tested until failure and the deflection, surface strains, internal steel strains, external steel strains and crack patterns were measured, the results were analyzed and conclusions were summarized. Finally, the recommendations were stated with the needed future work.
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