In this study, the effect of glass fiber reinforced polymer (GFRP) section and compressive strength of concrete in composite beams under static and low velocity impact loads was examined. Modeling was performed and the obtained results were compared with the test results and their compatibility was evaluated. Experimental tests of four composite beams were carried out, where two of them are control specimen with 20 MPa compressive strength of concrete deck slab and 50 MPa for other. Bending characteristics were affected by the strength of concrete under impact loading case, as it increased maximum impact force and damping time at a ratio of 59% and reduced the damping ratio by 47% compared to the reference hybrid beam. Under static loading, there was an increase in all the parameters, including the maximum load, ductility, and stiffness. Mid-span deflection was reduced by 25% under static and impact loads. A finite element analysis was performed by using the ABAQUS software. The midspan deflection value was greater than the experimental values by 6% and 3% for impact and static loads, respectively, and all other results showed a high rate of agreement with the obtained test results. The agreement between the numerical and experimental results indicates that the developed numerical model is capable of analyzing the impact and static behavior of such hybrid GFRP-concrete system. Doi: 10.28991/cej-2020-03091608 Full Text: PDF
This study is directed at investigating the liquefaction potential within earth dams using numerical modelling by two-dimensional finite element analyses method for considering the Makhool earth dam on the Tigris River in Iraq. The effect of peak ground acceleration of 0.02g, 0.04g, 0.06g, and 0.08g is viewed for a shell, and the crest is presented for all scaled earthquake duration 25 s, 50 s, 75 s, and 100 s. The current study program comprises selecting a representative history point within the Makhool earth dam as a case study. Many points were allocated at different locations within the shell and crest to observe the fluctuation in the factor of safety against liquefaction. The seepage analysis results viewed graphically for the operat
... Show MoreThis paper investigated the fatigue life behavior of two composite materials subjected to different times of shot peening (2, 4 and 6 min).The first material prepared from unsaturated polyester with E-glass reinforcement by 33% volume fraction. While, the second one was prepared from unsaturated polyester with aluminum powder by2.5% volume fraction. The experimental results showed that the improvement in endurance limit was obtained (for the first material) at 2, 4 and 6 min shot peening times where the percentage of maximum improvement was 25% at shot peening time of 6 min. While, the endurance limit of the second material decreased at shot peening times of 2, 4 and 6 min where the percentage of maximum reduction was 29 % at shot peenin
... Show MoreSteel Reinforced Concrete (RC) frequently faces durability problems. In certain areas, Glass Fiber-Reinforced Polymer (GFRP) rebars are considered a non-corrodible substitute for steel reinforcement. Elevated temperatures have a significant impact on the mechanical characteristics and the adhesiveness of GFRP rebars to concrete, particularly when the polymeric matrix's glass transition temperature is approached or surpassed. Three simply supported reinforced concrete slabs were considered in the experimental program. Each specimen had identical dimensions of 1500×540×120 mm. For the fire resistance requirements, a 45 mm clear concrete cover and an exception of a 200 mm unexposed (cool) anchor zone at the ends were considered. The
... Show MoreThis work investigates experimentally the effect of using a skirt with a square foundation of 100 mm width resting on dry gypseous soil (i.e., loose soil with 33% relative density), and subjected to an inclined load. Previous works did not study the use square skirted foundation rested on gypseous soil and subjected to inclined load. The investigated soil was brought from Tikrit city with 59% gypsum content. Standard physical and chemical tests on selected soil were carried out. Model laboratory tests were carried out to determine the effect of using a skirt with a square foundation on the load-settlement behavior of gypseous soil and subjected to inclined load with various Skirt depth (Ds) to foundation width (B) ratio
... Show MoreBackground: With the increase in composite material use in posterior teeth, the concerns about the polymerization shrinkage has increased with the concerns about the formation of marginal gaps in the oral cavity environment. New generation of adhesives called universal adhesive have been introduced to the market in order to reduce the technique sensitive bonding procedures to give the advantage of using the bonding system in any etching protocol without compromising the bonding strength. The aim of the study was to study marginal adaptation of two universal adhesives (Single bondâ„¢ Universal and Prime and Bond elect) using 3 etching techniques under thermal cycling aging. Materials and Methods: Forty-eight sound maxillary first premola
... Show MoreThe Sunnah of the Prophet has a great impact in building human behavior, and the formation of Islamic thought, has worked to spread science in all of Egypt, as it carried to the people of the eternal prophecy of the love of science, it was a source of knowledge and civilization. It is a generous source, a rich source of the Islamic nation, always tender, and renewed benefit, which is not only a source of legislation and language but is a source of guidance for thought and guidance of behavior, and the Hadith The importance is obvious In the integration of Islam, and show aspects of human integration in the personality of Mustafa , and the Muslims are interested in talking - collected and codification -, and made the effort of the cent
... Show MoreUsing fiber-reinforced polymer (FRP) could effectively improve the strength and endurance of reinforced concrete (RC) constructions. This study evaluated the flexural behavior of one-way concrete slabs with openings reinforced with glass fiber-reinforced polymers (GFRP) bars. It strengthened using carbon fiber-reinforced polymer (CFRP) sheets around the openings. The experimental program of this study is adopted by casting and testing four one-way concrete slabs with dimensions of (150*750*2650) mm. These slabs are divided into two groups based on whether they were strengthened or un-strengthened. For each group, two different openings (either one rectangular or two square) measured 250*500 mm and 250*250 mm, respective
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