In this study, a three-dimensional finite element analysis using ANSYS 12.1 program had been employed to simulate simply supported reinforced concrete (RC) T-beams with multiple web circular openings subjected to an impact loading. Three design parameters were considered, including size, location and number of the web openings. Twelve models of simply supported RC T-beams were subjected to one point of transient (impact) loading at mid span. Beams were simulated and analysis results were obtained in terms of mid span deflection-time histories and compared with the results of the solid reference one. The maximum mid span deflection is an important index for evaluating damage levels of the RC beams subjected to impact loading. Three experimental T-beams were considered in this study for calibration of the program. All models had an identical cross-section and span similar to those of the experimental beams. The diameter of the openings of the experimental beams was 110 mm. Three other diameters were varied (50, 80 and 130) mm. The location of the face of the opening with respect to the location of impact loading was investigated (the face of the opening at distance varied 0d, 0.5d, 1d and 1.5d from the location of loading, where d is the effective depth) and the number of web openings was varied (2,4 and 6) openings. All modeled beams subjected to dropping mass of 24.5 kg with height of drop of 250 mm (as for the experimental beams). Results obtained from this study showed that the behavior of beams with circular openings of diameter equal to 22% the web depth has a small effect on the response of the RC T-beams. On the other hand, introducing circular openings with a diameter equal to 35% and 57% of the web depth (80 and 130 mm) increases the maximum mid span deflection by 23% and 43% respectively. Results also showed that, openings with a distance greater than or equal to 1.5 d from the location of impact loading have no effect on the deflection of the RC beams.
During the last quarter century, many changes have taken place in the tanks industry and also in the materials that used in its production، while concrete is the most suitable material where concrete tanks has the benefits of strength, long service life and cost effectiveness. So, it is necessary improvement the
conventional concrete in order to adapt the severe environment requirements and as a result high
performance concrete (HPC) was used. It is not fundamentally different from the concrete used in the past, although it usually contains fly ash, ground granulated blast furnace slag and silica fume, as well as
superplasticizer. So, the content of cementitious material is high and the water/cement ratio is low. In this
stu
No-fine concrete (NFC) is cellular concrete and it’s light weight concrete produced with the exclusion of sand from the concrete. This study includes the mechanical properties of lightweight reinforced by steel fiber, containing different proportions of steel fiber. This study was done using number of tests. These tests were density, compressive strength, flexural strength and absorption. These tests of the molds at different curing time. The results of tests that implication of fiber to No. fine concrete did not affect significantly on the compressive strength, While the flexural strength were gets better. Results explained that, the flexural strength of (1%) fiber No- fine concrete molds are four times that of the reference mold
... Show MoreOne of the most important problems that faces the concrete industry in Iraq is the deterioration due to internal sulfate attack , since it reduces the compressive strength and increases the expansion of concrete. Consequently, the concrete structure may be damage .The effects of total and total effective sulfate contents on high strength concrete (HSC) have been studied in the present study.
The research studied the effect of sulfate content in cement , sand and gravel , as well as comparing the total sulfate content with the total effective SO3 content. Materials used were divided into two groups of SO3 in cement ,three groups of SO3 in sand ,and two groups of SO
... Show MoreFree cement refractory concrete is a type of refractory concrete with replacing alumina cement by bonding materials such as white kaolin, red kaolin and fumed silica. The free cement refractory concrete used in many applications like Petrochemicals, iron furnaces and cement production industries. The research clarifies the effect of steel fibers with two types crimped steel fibers and hooked steel
fibers with percentages 0.5%, 1% and 1.5% by volume from weight of bauxite aggregates. The additions of steel fibers with two types gave good properties in high temperatures where the specimens keep the dimension without failure and the properties made the best. the percentage of increasing for thermal conductivity was 44% for 1.5% crimped
The present investigation considers the effect of curing temperatures (30, 40, and 50˚C) and curing compound method on compressive strength development of high performance concrete, and compares the results with concrete cured at standard conditions and curing temperature (21˚C). The experimental results showed that at early ages, the rate of strength development at high curing temperature is greater than at lower curing temperature, the maximum increasing percentage in compressive strength is 10.83% at 50C˚ compared with 21C˚ in 7days curing age. However, at later ages, the strength achieved at higher curing temperature has been less, and the maximum percentage of reduction has been 5.70% at curing temperature 50C˚ compared with 21
... Show MoreThe present study aimed to assess the impact of seed Rhizobia treatment and potyvirus inoculation on bacterial nodulation and nitrogen fixation in cowpeas. The plants were infected with the virus two weeks post-germination. Nodules were present on the roots of plants treated with Rhizobia; however, almost no nodules were detected on untreated plants. The average number of nodules per plant on virus-inoculated plants was significantly lower than the average number per noninoculated plant. The virus caused a substantial decrease in the weight of nodules also. The study revealed that the presence of Rhizobia resulted in a significant rise in nitrogen content in the foliage. Specifically, the nitrogen percentage increased from 1.29% in plants n
... Show MoreThe growth curves of the children are the most commonly used tools to assess the general welfare of society. Particularity child being one of the pillars to develop society; through these tools, we can path a child's growth physiology. The Centile line is of the important tools to build these curves, which give an accurate interpretation of the information society, also respond with illustration variable age. To build standard growth curves for BMI, we use BMI as an index. LMSP method used for finding the Centile line which depends on four curves represents Median, Coefficient of Variation, Skews, and Kurtosis. These can be obtained by modeling four parameters as nonparametric Smoothing functions for the illustration variable. Ma
... Show MoreThe international standing has an impact on the strategic importance of the country in its relations with other regional and international countries. The strategic position of Taiwan has an impact on the US-Chinese relations, as it is one of the most important issues that raise dispute between the two countries. The while the Chinese consider Taiwan is an ancient legacy of their republic, and an integral part of it, the Americans consider it as an area linking the U.S. to the Asia-Pacific region, through which it intends to help its allies (Japan and South Korea). Moreover, Taiwan has huge economic importance as it is one of the largest manufacturers of electronic chips and semiconductors. This fact represents one of the most important issu
... Show MoreThis study investigates successive carriage, a distinct legal and commercial form of international transport, arising from the absence or irregularity of direct transport routes. Under this system, multiple carriers perform consecutive stages of transport under a single document, with the first carrier fully liable to the consignor or passenger, including breaches in subsequent stages. The research examines the role of direct and indirect transport documents and the concept of recourse, allowing a carrier who has compensated an injured party to seek reimbursement from other carriers. It highlights carriers’ duties to inspect goods, document their condition, and collect freight, and critically analyzes maritime carrier liability under Iraq
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