Alkali-Treated Agave Americana Fiber for Reinforcement of Fly Ash-Based Geopolymers

ABSTRACT

The mechanical properties of Agave americana fibers treated with NaOH solutions (1, 5, and 20 wt.%) for different times (0.5, 1 and 3 h) were investigated. At these conditions, tensile strength and ultimate strain of the fibers were determined. The treatment that required the minimum resources to improve the mechanical performance was 1% NaOH for 1 h. Fiber surface after the alkaline treatment was analyzed by scanning electron microscopy (SEM); it showed partial remotion of impurities at the mildest condition (1% NaOH for 0.5 h) and an apparent surface decomposition when using the most harsh condition (20% NaOH for 3 h). Fly ash-based geopolymer composites with different treated fiber contents were prepared. The compressive, flexural, and splitting tensile strengths of the composite geopolymers at seven days of age were determined. Results indicated that the addition of fibers slightly influenced the compressive strength; however, the ductility capacity was improved by up to 26% when 1% of treated fiber was incorporated. Regarding the tensile behavior, results indicate a direct relationship of strength with the amount of fibers, up to 36% improvement with 1% fiber content. Morphological of the fiber-reinforced geopolymer matrices was finally studied by SEM.

摘要

研究了经NaOH溶液(1、5和20 wt.%)处理不同时间(0.5、1和3 h)的龙舌兰纤维的力学性能. 在这些条件下,测定了纤维的抗拉强度和极限应变. 改善机械性能所需资源最少的处理为1%NaOH,持续1h. 用扫描电镜(SEM)分析了碱处理后的纤维表面;在最温和的条件下(1%NaOH,持续0.5小时)杂质部分去除,在最苛刻的条件下(20%NaOH,持续3小时)表面明显分解. 制备了不同处理纤维含量的粉煤灰基地质聚合物复合材料. 测定了复合地质聚合物在七天龄期的抗压、弯曲和劈裂抗拉强度. 结果表明,纤维的加入对抗压强度影响不大;然而,当加入1%的处理过的纤维时,延性能力提高了26%. 关于拉伸性能,结果表明强度与纤维数量直接相关,纤维含量为1%时,强度提高36%. 最后用扫描电镜研究了纤维增强地质聚合物基体的形态.

KEYWORDS:

• Natural fiber
• alkaline treatment
• fly ash-based geopolymer
• fiber-reinforced geopolymer composite
• Mechanical Properties

关键词:

• 天然纤维
• 碱处理
• 粉煤灰基地质聚合物
• 纤维增强地质聚合物复合材料
• 机械性能

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by CONCYTEC [J108-2016] under the ERANetLAC project [ELAC2015/T02-0721]: “Development of eco-friendly composite materials based on geopolymer matrix and reinforced with waste fibers.