A comparative analysis of the chemical composition and compliance level to established standards of concrete reinforcement steel rods rolled in Nigeria

Heliyon

Lawson O. Adekoya¹  Sunday O. Oyedepo²  Samson O. Adeosun²  Richard O. Leramo²  Oluseyi O. Ajayi²  Ojo S.I. Fayomi²  Stephen E. Eluwa²  Oluwaseun Kilanko³  Olayinka S. Ohunakin⁴  Nicholas T. Leramo⁵  Peter O. Aiyedun⁶  Phillip O. Babalola⁷ 

[1] Corresponding author.;Mechanical Engineering Department, Covenant University, Ogun State, Nigeria;Mechanical Engineering Department, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria;Mechanical Engineering Department, University of Agriculture, Abeokuta, Nigeria;Metallurgical and Materials Engineering Department, University of Lagos, Nigeria;Nigeria Security and Civil Defence Corps, Oyo State Command, Ibadan, Nigeria;Orient Concept, Jamade Quarters, Apete Ibadan, Oyo State, Nigeria;

关键词: Chemical composition;    Steel reinforcing bars;    Locally-rolled;    Billets;    Scraps;    Standards;   

DOI  :  

来源: DOAJ

【 摘 要 】

Nigeria is presently facing the challenges of collapsing buildings and bridges due to substandard materials used as reinforcement products. The increasing use of scraps as feedstock for the production of reinforcing steel bars by steel rolling mill companies has adversely affected the quality of rebars in Nigeria. This research study aimed to appraise the chemical properties of selected brands of steel rebars of Nigeria. Thirty selected brands of rebars were sourced from the six geopolitical zones in Nigeria, and their chemical compositions were analysed for level of compliance with five selected standards (SON, BSI, ASTM, AISI, ISO). The chemical composition test was performed using Optical Light Spectrometric methods. One way analysis of variance (ANOVA) test was performed using SPSS version 20 to examine whether significant differences exist or not in mean chemical composition for the different categories of selected steel rods. Statistical analysis shows a significant difference (P < 0.05) in chemical composition and compliance level between the different types of selected steel rods. The imported steel rods recorded the highest mean (μ = 101.4) in terms of chemical composition and compliance, followed by locally rolled from imported billets (μ = 101.2), TMT steel rods (μ = 101.0), and ordinary steel rods (μ = 100.6). Concerning CEV1 and CEV2, it was observed that all the brands were fully compliant within the maximum permissible ranges given in the local, foreign and international standards except an ordinary steel bar of Brand 16, which has value beyond the specified limits of CEV1. This study also shows that all imported and 77.8% of locally-rolled steel bars are low-carbon steel as specified by the selected standards.

【 授权许可】

Unknown