Abstract

Many environmental problems can be ascribed to agricultural waste. Millions of tonnes of agricultural waste, such as banana and date palm trees, are produced worldwide. Such waste is converted and recycled as natural fiber. On the other hand, a major problem of high-strength concrete (HSC) is the sudden failure at the ultimate capacity of concrete. To solve these problems, this work investigated the effects of using natural fiber waste to improve the brittle behavior of HSC. The natural fiber was treated with chemical solutions before recycling in concrete. Seven HSC mixes were designed; three mixes contained banana fiber (BF), the other three incorporated palm leaf sheath fiber (PLSF), and the last one was the control mix. The respective fiber volume fractions of BF and PLSF were 1%, 2% and 3%, and the aspect ratio was 100. The fresh and hardened properties, such as slump, compressive, tensile, flexural strengths and modulus of elasticity, of HSC with natural fiber were determined. In addition, microstructure analysis of natural fibers and HSC with natural fiber was performed through scanning electron microscopy. No substantial improvement was observed in the compressive strength of the natural fiber. The tensile strength of HSC increased when up to 2% PLSF was used. Compared with BF, PLSF yielded a higher enhancement in HSC properties. Both fibers demonstrated improved efficiency in enhancing the brittle behavior of HSC.

• Highlights

• The effects of recycling an agriculture fiber in concrete are reported.

• Using PLSF in HSC yields higher improvement compared with using BF.

• BF and PLSF achieve high efficiency in arresting the crack developed in HSC.

摘要

许多环境问题可归因于农业废弃物。全球产生了数百万吨的农业废弃物，例如香蕉树和枣椰树。这些废物被转化和回收为天然纤维。另一方面，高强混凝土（HSC）的一个主要问题是混凝土极限承载力的突然破坏。为了解决这些问题，本工作研究了使用天然纤维废料改善 HSC 脆性行为的效果。在回收到混凝土中之前，天然纤维经过化学溶液处理。设计了七种 HSC 混合物；三种混合物含有香蕉纤维（BF），另外三种含有棕榈叶鞘纤维（PLSF），最后一种是对照混合物。BF和PLSF的纤维体积分数分别为1%、2%和3%，纵横比为100。测定了 HSC 与天然纤维的新鲜和硬化性能，如坍落度、压缩、拉伸、弯曲强度和弹性模量。此外，通过扫描电子显微镜对天然纤维和含有天然纤维的HSC进行微观结构分析。天然纤维的抗压强度没有明显改善。当使用高达 2% 的 PLSF 时，HSC 的拉伸强度增加。与 BF 相比，PLSF 在 HSC 性能方面产生了更高的增强。两种纤维都表现出提高 HSC 脆性行为的效率。通过扫描电子显微镜对天然纤维和含有天然纤维的HSC进行微观结构分析。天然纤维的抗压强度没有明显改善。当使用高达 2% 的 PLSF 时，HSC 的拉伸强度增加。与 BF 相比，PLSF 在 HSC 性能方面产生了更高的增强。两种纤维都表现出提高 HSC 脆性行为的效率。通过扫描电子显微镜对天然纤维和含有天然纤维的HSC进行微观结构分析。天然纤维的抗压强度没有明显改善。当使用高达 2% 的 PLSF 时，HSC 的拉伸强度增加。与 BF 相比，PLSF 在 HSC 性能方面产生了更高的增强。两种纤维都表现出提高 HSC 脆性行为的效率。

• 强调

• 报告了在混凝土中回收农业纤维的效果。

• 与使用 BF 相比，在 HSC 中使用 PLSF 会产生更高的改进。

• BF 和 PLSF 在阻止 HSC 中产生的裂纹方面取得了很高的效率。