Ductility of simply supported rubberized concrete beams

2021 ◽  
Vol 12 (2) ◽  
pp. 49
Author(s):  
Ahmed Youssef Kamal

Dispose of waste rubberized tires become a dangerous problem around the world, represented a big serious risk to the sur-rounded environment. Many studies show that over 1000 million tires reach their expired date yearly and this figure is anticipated to be 5000 million tires by reaching 2030. A minor part of them is employed as recycled materials and the residual amount is stockpiled or buried. This paper aimed to successfully utilize the vast amounts of tire rubber waste existing currently in landfills. This paper represents a practical investigation of the ductility performance of the reinforced rubberized concrete beams. Thirteen reinforced concrete beams simply supported, with waste rubber tires mixtures vary from 0 to 8 percentage as aggregates replacements, were tested by mid-span load. Therefore, to examine the ductility performance of reinforced rubberized concrete beams, three sets of samples were made. In the first group, coarse aggregates in the concrete mix were replaced by different percentages of the waste rubber partials, while for the second group, crumb rubber was replaced for the fine aggregates, and for the third one, a mix of waste and crumbed rubber were replaced for both types of aggregates. Experimental results of rubberized specimens were also compared with that of the reference beam (without rubber replacement), the comparison results declare that concrete contains rubber particles is less ductile than conventional concrete.

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.


2018 ◽  
Vol 7 (1) ◽  
pp. 126
Author(s):  
Latha M S ◽  
Revanasiddappa M ◽  
Naveen Kumar B M

An experimental investigation was carried out to study shear carrying capacity and ultimate flexural moment of reinforced cement concrete beam. Two series of simply supported beams were prepared by varying diameter and spacing of shear and flexural reinforcement. Beams of cross section 230 mm X 300 mm and length of 2000 mm. During testing, maximum load, first crack load, deflection of beams were recorded. Test results indicated that decreasing shear spacing and decreasing its diameter resulted in decrease in deflection of beam and increase in bending moment and shear force of beam.


2018 ◽  
Vol 7 (4.20) ◽  
pp. 316 ◽  
Author(s):  
Adel A. Al-Azzawi ◽  
Dalia Shakir ◽  
Noora Saad

In Iraq, the use of rubber waste material in concrete is an interesting topic due to its availability in large volumes. Researches of applications of rubber waste in concrete have been increased since 2003. Many studies carried out to investigate the performance of concrete using different ratios of rubber as a replacement to fine or coarse aggregate. In this research, rubber wastes from scrapped tires have been added as fiber to concrete mix with presence of 0.5% superplasticizer. The flexural behavior of concrete beams, mechanical properties of concrete and workability of concrete mixes have been studied. Rubber fibers ranging from (2-4) mm were added in percentages of 0.5% and 1%) of the cement weight. The results have demonstrated that the addition of rubber material as fibers in natural aggregate concrete enhances its ductility, compressive strength and tensile strength compared to the normal concrete. The effect of rubber fiber content is found to be significant on the behavior of tested beams. If the fiber content increased from 0 to 0.5% the cracking load increased by 60 % and ultimate load increased by 21%. For rubberized concrete, if the fiber content increased from 0.5 to 1.0%, the cracking load decreased 7% and ultimate load increased by 4%.   


2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.


2005 ◽  
Vol 32 (6) ◽  
pp. 1075-1081 ◽  
Author(s):  
Ashraf M Ghaly ◽  
James D Cahill IV

Waste rubber tires that cannot be processed for useful applications are numbered in the millions around the world. The build up of old rubber tires in landfills is commonly considered a major threat to the environment, and it is unquestionably a burden on landfill space. This research project was an investigation into the possibility of using fine rubber particles in concrete mixtures. The experimental testing program was designed to study the effect of the addition of crumb rubber, as replacement of a portion of fine aggregates (sand), on the strength of concrete. Rubber was added to concrete in quantities of 5%, 10%, and 15% by volume of the mixture. Three different water/cement ratios were used: 0.47, 0.54, and 0.61. A total of 180 concrete cubes were made. The cubes were tested in compression at 1, 7, 14, 21, and 28 d with the load continuously and automatically measured until failure. The load values were used to calculate compressive stress as related to different rubber contents and water/cement ratios. Compression test results were used to develop several plots relating rubber content and water/cement ratio to compressive stress of concrete. Test results gathered in this research project indicated that the addition of crumb rubber to concrete results in a reduced strength as compared with that of conventional concrete. Based on the experimental results, correlations have been developed to estimate the reduction in concrete strength as a function of the rubber content in the mix.Key words: compressive strength, concrete, crumb rubber, rubberized concrete.


2021 ◽  
Vol 318 ◽  
pp. 03016
Author(s):  
Khalid I. Qaddoory ◽  
Ahmed A. Mansor ◽  
Ahlam S. Mohammed ◽  
Bilal J. Noman

In the past few years, new techniques have emerged using steel plates instead of traditional reinforcement in the reinforced concrete beams. This study deals with using a new method for reinforced concrete beams using steel plates instead of traditional steel bars with different thicknesses of (4, 5, and 6 mm) placed vertically inside the lower part of the beam. Four reinforced concrete beams were cast and tested under a two-point load. All beams had the same cross-sectional area of reinforcement and dimensions of 2100 mm in length, 350 mm in height, and 250 in width. The results showed that as the thickness of the steel plate increases, the samples would have greater resistance until more deflection is produced. In addition, there is a reduction in the crack load, ultimate load, and yield load when replacing reinforcing bars with steel plates. In which, a reduction in crack load by about 11.1, 15.5, and 22.2% plate thicknesses of 4,5,6 mm respectively, compared to reference beam that had a deformed steel bar (Dia. 16 mm). In addition, a reduction in yielding load was observed about 42, 53, and 60% for steel plate thickness of 4, 5, and 6 mm respectively, compared to the reference model. Finally, the cracks for all the steel plate specimens compared to reference specimens were wider and smaller.


2019 ◽  
Vol 27 (1) ◽  
pp. 247-261
Author(s):  
Abass Oda Dawood ◽  
Hamsa Mahir Adnan

This research is aimed to study the possibility of recycled the PET wastes by forming the PET wastes as plastic semi-bars and used it as tension bars in simply supported reinforced concrete beams . Twelve beams specimens with dimension of (150*200*1400) mm are casted and tested to monitoring the effecting of these wastes as tension bars on the strengths and serviceability of reinforced concrete beams. The mechanical properties (compressive, splitting tensile and flexural strength) are evaluated in which specimens tested in age of 28 days. The tests results showed that all presented plastic semi-bars are failed except one case in which the deformed steel bar are used with additional layer of PET bottle cut into two parts which showed an increment in ultimate failure load and deflection of  3.03 % and 213.83 % respectively, larger than the reference beam specimens. Negatively effect of PET semi-bar on ultimate load of beams is due to bonding failure between PET bars and surrounding concrete, which made the PET bars as voids or weak region within beam cross section.


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