Sharaky Ibrahim A, Elamary Ahmed S, Alharthi Yasir M, Abdo Ayman
Civil Engineering Department, College of Engineering, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
Structural Engineering Department, Faculty of Engineering, Zagazig University, Zagazig P.O. Box 44519, Egypt.
Polymers (Basel). 2022 Dec 7;14(24):5351. doi: 10.3390/polym14245351.
The huge amounts of old and damaged tires spread worldwide has caused many complex environmental risks. The old tires have been converted to crumb rubber (CR) and tire recycled steel fiber (RSF) to facilitate their use. This study used CR to partially replace natural sand in reinforced (RC) columns. Externally bonded (EB) carbon-fiber-reinforced polymer (CFRP) laminates, welded wire mesh (WWM), and RSF were used to enhance the axial behavior of the tested columns to overcome the concrete deficiencies resulting from the inclusion of the CR instead of natural sand. Eighteen columns were prepared and tested to discuss the effects of strengthening type, CR content, RSF, and strengthening area on the axial behavior of the RC columns. Certain columns were internally reinforced with WWM, while others were externally strengthened with EB CFRP laminates. Partially or fully EB CFRP laminates were used to strengthen the columns. Moreover, one column was cast with NC and 0.2% RSF to investigate the role of RSF in confining the column. The results demonstrated a concrete strength reduction for the rubberized concrete (CRC) as the CR content increased. Conversely, the strengthened columns experienced higher load capacities than the corresponding un-strengthened ones cast with the same concrete mix. Moreover, adding 2% RSF to the NC mix could enhance the column capacity, although it decreased the concrete strength. Furthermore, using two CFRP layers increased the load capacity and ductility of the strengthened columns. The strengthened column cast with 50% CR showed the highest load efficiency (334.3% compared to the un-strengthened one).
全球范围内大量废旧和损坏轮胎造成了诸多复杂的环境风险。废旧轮胎已被加工成胶粉（CR）和轮胎再生钢纤维（RSF），以便于利用。本研究使用胶粉部分替代钢筋混凝土（RC）柱中的天然砂。采用外部粘贴（EB）碳纤维增强聚合物（CFRP）板、焊接钢丝网（WWM）和轮胎再生钢纤维来增强试验柱的轴向性能，以克服因用胶粉替代天然砂而导致的混凝土性能缺陷。制备并测试了18根柱，以探讨加固类型、胶粉含量、轮胎再生钢纤维和加固面积对钢筋混凝土柱轴向性能的影响。部分柱内部采用焊接钢丝网加固，而其他柱则采用外部粘贴碳纤维增强聚合物板加固。使用部分或全部外部粘贴碳纤维增强聚合物板对柱进行加固。此外，浇筑了一根普通混凝土（NC）柱并掺入0.2%的轮胎再生钢纤维，以研究轮胎再生钢纤维在约束柱方面的作用。结果表明，随着胶粉含量的增加，橡胶混凝土（CRC）的强度降低。相反，加固后的柱比采用相同混凝土配合比浇筑的相应未加固柱具有更高的承载能力。此外，在普通混凝土配合比中添加2%的轮胎再生钢纤维可提高柱的承载能力，尽管这会降低混凝土强度。此外，使用两层碳纤维增强聚合物板可提高加固柱的承载能力和延性。采用50%胶粉浇筑的加固柱显示出最高的荷载效率（与未加固柱相比为334.3%）。
