Gao Chang, Fu Qiuni, Huang Liang, Yan Libo, Gu Guangming
College of Civil Engineering, Hunan University, Changsha 410082, China.
Department of Organic and Wood-Based Construction Materials, Technische Universität Braunschweig, Hopfengarten 20, 38102 Braunschweig, Germany.
Polymers (Basel). 2022 Mar 21;14(6):1260. doi: 10.3390/polym14061260.
In this study, the compressive performance of sisal fiber-reinforced recycled aggregate concrete (SFRAC) composite, confined with jute fiber-reinforced polymer (JFRP) tube (the structure was termed as JFRP-SFRAC) was assessed. A total of 36 cylindrical specimens were tested under uniaxial compression. Three major experimental variables were investigated: (1) the compressive strength of concrete core (i.e., 25.0 MPa and 32.5 MPa), (2) jute fiber orientation angle with respect to the hoop direction of a JFRP tube (i.e., β = 0°, 30° and 45°), and (3) the reinforcement of sisal fiber (i.e., 0% and 0.3% by mass of cement). This study revealed that the prefabricated JFRP tube resulted in a significant enhancement of the compressive strength and deformation ability of RAC and SFRAC. The enhancements in strength and ultimate strain of the composite columns were more pronounced for concrete with a higher strength. The strength and ultimate strain of JFRP-confined specimens decreased with an increase in fiber orientation angle β from 0° to 45°. The sisal fiber reinforcement effectively improved the integrity of the RAC and reduced the propagation of cracks in RAC. The stress-strain behaviors of JFRP-RAC and JFRP-SFRAC were predicted by the Lam and Teng's model with the revised ultimate condition equations.
在本研究中，评估了用黄麻纤维增强聚合物（JFRP）管约束的剑麻纤维增强再生骨料混凝土（SFRAC）复合材料（该结构称为JFRP-SFRAC）的抗压性能。总共36个圆柱形试件在单轴压缩下进行了测试。研究了三个主要实验变量：（1）混凝土芯的抗压强度（即25.0MPa和32.5MPa），（2）黄麻纤维相对于JFRP管环向的取向角（即β = 0°、30°和45°），以及（3）剑麻纤维的增强作用（即水泥质量的0%和0.3%）。本研究表明，预制JFRP管显著提高了再生骨料混凝土（RAC）和剑麻纤维增强再生骨料混凝土（SFRAC）的抗压强度和变形能力。对于强度较高的混凝土，复合柱的强度和极限应变增强更为明显。随着纤维取向角β从0°增加到45°，JFRP约束试件的强度和极限应变降低。剑麻纤维增强有效地改善了再生骨料混凝土的整体性，并减少了再生骨料混凝土中裂缝的扩展。采用修正极限条件方程的Lam和Teng模型预测了JFRP-RAC和JFRP-SFRAC的应力-应变行为。
