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T.C. Nwofor, F.K. Malkani
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- Senior Lecturer, Student Department of Civil and Environmental Engineering University of Port Harcourt, Department of Civil and Environmental Engineering University of Port Harcourt Rivers State, Rivers State Nigeria, Nigeria
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Abstract
nThis research delves into the effect of using various single coarse aggregate sizes and combinations of such by specific proportions. A thorough examination involving control specimens of 12mm, 20mm, and 25mm aggregates sizes, with combining proportions in the ratios – 5/8:3/8, 1/2:1/2, 3/8:5/8 have been conducted, shedding light on critical patterns that dictate concrete performance. The fine aggregate was properly zoned from the preliminary test. The design mix was calculated for a characteristic strength of 15N/mm2. The concrete mixes were in batches, each containing a single coarse aggregate size or a blend of two different coarse aggregate sizes. Crushed aggregate (Granite) was used in this experiment. The study reveals a consistent trend wherein mixes with larger single-sized coarse aggregates demonstrate superior compressive strengths, aligning with established principles of concrete technology. However, improvements were observed upon the use of an optimization ratio to combine different coarse aggregate sizes into a blend. Two standout mixes, E (12mm: 20mm – 5/8:3/8) with compressive strength of 21.4N/mm2 and 26.6N/mm2 and K (20mm: 25mm – 5/8:3/8) with compressive strength of 29.1N/mm2 and 33.3N/mm2, consistently exhibited remarkable strengths at 7 and 28 days respectively. The success of these mixes underscores the pivotal role of specific aggregate sizes and proportions in optimizing concrete performance. The findings offer practical recommendations, emphasizing the importance of carefully tailoring aggregate gradation, exploring effective ratios such as 5/8:3/8, and systematically monitoring strength development over time. This research not only contributes valuable insights for concrete mix design but also provides engineers with a nuanced understanding of how aggregate gradation influences compressive strength.
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Keywords: compressive strength, combined gradation, crushed aggregate, preliminary test, aggregate gradation, design mix, optimizing concrete
n[if 424 equals=”Regular Issue”][This article belongs to Recent Trends in Civil Engineering & Technology(rtcet)]
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References
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| Volume | 14 | |
| [if 424 equals=”Regular Issue”]Issue[/if 424][if 424 equals=”Special Issue”]Special Issue[/if 424] [if 424 equals=”Conference”][/if 424] | 01 | |
| Received | February 1, 2024 | |
| Accepted | March 29, 2024 | |
| Published | April 30, 2024 |
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