Ghoneim Mohamed, Yehia Ayatollah, Yehia Sherif, Abuzaid Wael
Civil Engineering Department, American University of Sharjah (AUS), Sharjah P.O. Box 26666, UAE.
Department of Engineering Systems and Environment, University of Virginia, Charlottesville, VA 22903, USA.
Materials (Basel). 2020 Sep 20;13(18):4183. doi: 10.3390/ma13184183.
In this paper, shear strength of fiber reinforced recycled concrete was investigated. A Self Consolidated Concrete (SCC) matrix with 100% coarse recycled aggregate and different types of fibers were used in the study. Steel (3D and 5D), synthetic and hybrid fibers with a volume fraction of 0.75% were added to the concrete matrix to prepare eight beams. In addition, two beams were cast without fibers as control specimens. All beams were prepared without shear reinforcement and were tested to evaluate concrete contribution to the shear capacity. In addition, optical images were captured to allow for full-field displacement measurements using Digital Image Correlation (DIC). The results showed about 23.44-64.48% improvement in the average concrete shear capacity for fiber-reinforced beams when compared to that of the control specimens. The percentage improvement was affected by fiber type and the steel fiber beams achieved the best performance. The addition of the fiber delayed the crack initiation and improved the post-cracking and ductile behavior of all beams. Moreover, the experimental results were compared to those predicted by codes and proposed equations found in the literature for concrete strength with and without fibers.
本文对纤维增强再生混凝土的抗剪强度进行了研究。本研究采用了一种以100%粗再生骨料为基体的自密实混凝土（SCC）以及不同类型的纤维。向混凝土基体中添加体积分数为0.75%的钢纤维（3D和5D）、合成纤维和混杂纤维，制备了八根梁。此外，浇筑两根无纤维梁作为对照试件。所有梁均未设置抗剪钢筋，并通过试验评估混凝土对抗剪承载力的贡献。此外，还采集了光学图像，以便使用数字图像相关技术（DIC）进行全场位移测量。结果表明，与对照试件相比，纤维增强梁的平均混凝土抗剪承载力提高了约23.44% - 64.48%。提高的百分比受纤维类型影响，钢纤维梁性能最佳。纤维的加入延迟了裂缝的产生，并改善了所有梁的开裂后性能和延性。此外，还将试验结果与规范预测结果以及文献中针对有纤维和无纤维混凝土强度提出的公式进行了比较。
