Environment
U. N. Wilson; J. E. Sani; A. Yusuf; O. C. Eze
Abstract
This research work examined the effect of jute fibre on the shear strength of concrete. Fibre volume fractions of 0%, 0.25%, 0.5%, and 0.75% for grades 25, 30, 35 and 40 N/mm2 respectively were used. A total of 32 beams and 96 cubes were prepared. 16 beams and 48 cubes were cured at room temperature ...
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This research work examined the effect of jute fibre on the shear strength of concrete. Fibre volume fractions of 0%, 0.25%, 0.5%, and 0.75% for grades 25, 30, 35 and 40 N/mm2 respectively were used. A total of 32 beams and 96 cubes were prepared. 16 beams and 48 cubes were cured at room temperature for 28 days, while the other 16 beams and 48 cubes were cured for 28 days and kept for a period of 6 months to be observed for durability with respect to strength after testing. All the beams were tested under three-point loading system with a shear span, av = 2.5d. The results of the compressive strength showed that concrete made with 0.5% jute fibre for 28 days and 6 months gave percentage increase in compressive strength by 12%, 12.5%, 9.7% and 10.1% for grades 25, 30, 35 and 40 N/mm2 respectively compared to the control samples. Percentage increase in shear strength were by 24.5%, 16.1%, 27.9% and 16.5% for concrete grades 25, 30, 35 and 40 N/mm2 respectively compared to the control samples. The addition of the fibre to the concrete slightly reduced the workability of the concrete and increased the crack resistance of concrete.
Environment
S. O. Odeyemi; R. Abdulwahab; M. A. Akinpelu; R. Afolabi; O. D. Atoyebi
Abstract
The rising cost of concrete production due to the global recession in world economy caused by the COVID-19 pandemic and the greenhouse gases emitted in the production of cement has necessitated the need for alternative materials for cement. In this study, bamboo strips and steel rebars were used as reinforcements ...
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The rising cost of concrete production due to the global recession in world economy caused by the COVID-19 pandemic and the greenhouse gases emitted in the production of cement has necessitated the need for alternative materials for cement. In this study, bamboo strips and steel rebars were used as reinforcements in a ternary blended concrete to determine their strength properties. In alignment with standard requirements for testing, concrete specimens were tested at curing ages of 7, 14 and 28 days for compressive, splitting tensile and flexural strengths. The morphological and bond characteristics of the bamboo were determined through the Scanning Electron Microscopy (SEM) and Fourier Transform Infra-Red Spectroscopy (FTIR), respectively; while its tensile strength was determined and compared with that of steel reinforcement. These results showed that bamboo is ductile and has stretching vibrational spectrum. The combinations of quarry dust, river sand, Rice Husk Ash (RHA) and Guinea Corn Husk Ash (GCHA) yielded compressive and split tensile strengths of 20.4 N/mm2 and 2.18 N/mm2, respectively. Concrete with 50 % river sand and 50 % quarry dust performed better in flexure for both Bamboo Reinforced Concrete (BRC) and Steel Reinforced Concrete (SRC) at 28 days with strengths of 12.75 N/mm2 and 22.49 N/mm2, respectively. Therefore, bamboo, quarry dust, rice husk and guinea corn husk ash can be used for reinforced concrete production.
V. N. Kanthe
Abstract
In this research work, the effect of rice husk ash (RHA) along with and without superplasticizer (SP) on the properties of concrete was investigated. The good workability and compaction is key parameter for strength and durability of concrete, and it may achieved by adding SP in to the concrete. ...
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In this research work, the effect of rice husk ash (RHA) along with and without superplasticizer (SP) on the properties of concrete was investigated. The good workability and compaction is key parameter for strength and durability of concrete, and it may achieved by adding SP in to the concrete. In India RHA is available in huge quantity. It is byproduct of agriculture. In present research ordinary portland cement (OPC) was replaced by 10 to 50% RHA. The fresh properties as workability and hardened properties of concrete as compressive strength were examined. For durability test water absorption, acid attack and sulphate attack tests were conducted.The test results show that at 10%RHA with SP the maximum strength of concrete was attained with respect to control concrete mix (CM). The satisfactory test results were shown for durability and strength. Such kind of blend concrete is more efficient to enhance the properties of concrete which reduce the consumption of cement. The utilization of agricultural byproduct makes concrete sustainable and reduce environmental problems.
O. Hadad; O. Soltani; H. Azizian; V. Mam Ghaderi
Abstract
Due to the increasing use of concrete, researchers and engineers are constantly tried to improve its mechanical and physical properties as well as its efficiency. Hence, they have made use of the most diverse products and the most modern concere technologies. In the present study, oak bark ash and macro ...
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Due to the increasing use of concrete, researchers and engineers are constantly tried to improve its mechanical and physical properties as well as its efficiency. Hence, they have made use of the most diverse products and the most modern concere technologies. In the present study, oak bark ash and macro fly ash have been used as the most widely used pozzolans in the concrete industry. The parameters of concrete and the percentages of materials used in its structure remained constant, but different percentages of oak bark ash and macro fly ash have been added to the mix design. Brazilian method and bending strength of concrete was applied. The parameters of concrete density, concrete consistency, compressive strength, and tensile strength have been investigated..Therefore, the existing materials required necessary tests; based on obtained resulted, an optimal design for the concrete mix was introduced from which the necessary specimens were taken into consideration. Then, oak bark ash was used as an additive, in proportions of 0.2 and 0.4% by the total weight of cement, and macro fly ash was used to replace cement as a variable in various proportions of 5, 10, 15 and 20% by total weight of cement. Based on the existing variables and the control design, a total of 15 groups of mix designs were introduced. The statistical population includes 45 cubic specimens (15×15×15), and 45 cylindrical specimens (15×30) for tensile strength test using Brazilian method. Also 45 bending beam specimens having dimensions of 10×10×50 were examined. Finally, after analysis of the obtained results, we dentified the superior mix design had the best performance and that both additives affected all studied parameters, including concrete consistency, density, compressive strength, tensile strength, and bending strength of concrete. However, macro fly ash had a great effect on the conrete strength. The obtained results also indicated that excessive use of any additive could have adverse effects on the mechanical properties of the concrete.