Flexural Behavior of High Strength RC Beams Incorporating Nano-Silica and Macro-Polypropylene Fiber


  • Araz Ali Mohammed Civil Engineering Department, College of Engineering, University of Sulaimani, Sulaymaniyah, Kurdistan Region, Iraq; Civil Engineering Department, College of Engineering, University of Raparin, Rania, Kurdistan Region, Iraq
  • Najmadeen M. Saeed Civil Engineering Department, College of Engineering, University of Raparin, Rania, Kurdistan Region, Iraq; Civil Engineering Department, Faculty of Engineering, Tishk International University, Erbil, Kurdistan Region, Iraq http://orcid.org/0000-0001-7074-0256




RC Beams, Flexural Strength, Mechanical Properties, Nano-Silica, Polypropylene Fiber


This paper investigates the flexural behavior of high-strength RC beams experimentally to assess the effect of Nano-silica (NS) and Macro-Synthetic High Strength Polypropylene Fiber (MPF). Ordinary Portland cement was partially replaced by the NS and MPF with different proportions to produce four concrete mixtures. Tests were conducted on the full-scale high-strength RC beams, including first crack load, failure load, deflection, concrete strain, steel strain, and mode failure, which were examined and compared. In addition, the tests on the mechanical properties of high-strength concrete mixtures were also conducted at the ages of 28 and 56 days. The test results concluded that the addition of NS and MPF significantly improved the first-cracking and failure loads and decreased deflection at levels of cracking and failure loads. Additionally, an increase in NS content resulted in a minor increase in the ultimate strain related to the failure loads. Furthermore, the mix of 3% NS with 0.5% MPF was found to lead to the highest mechanical characteristics of concrete. The improvements were the concrete compressive strength by 33.6%, split tensile strength by up to 54.1%, and flexural strength by up to 28.3% compared with control specimens.


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Author Biography

  • Najmadeen M. Saeed, Civil Engineering Department, College of Engineering, University of Raparin, Rania, Kurdistan Region, Iraq; Civil Engineering Department, Faculty of Engineering, Tishk International University, Erbil, Kurdistan Region, Iraq

    Dr. Najmadeen is an assistant professor of civil/structural engineering in the civil engineering department and head of the engineering consulting office at the University of Raparin. He was graduated as a doctor of civil/structural engineering from Cardiff University-UK in 2014. Dr. Najmadeen has 15 publications (in refereed international journals). He has experience in Force Method, Prestress Analysis, Displacement Control, Optimization, Deployable Structure, Structural Morphology, Foldable Structures, Pantographic Structures, Geometric Nonlinearity, Cable Structure, Cable Nets Structural Optimization, and Shape Optimization.


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Research Articles

How to Cite

Flexural Behavior of High Strength RC Beams Incorporating Nano-Silica and Macro-Polypropylene Fiber. (2022). UKH Journal of Science and Engineering, 6(2), 83-96. https://doi.org/10.25079/ukhjse.v6n2y2022.pp83-96