Mechanical Behavior of the Alkali-Treated Ichu Fiber-Cementitious Matrix Interface Through Experimental Tests, Numerical, and Analytical Models

ABSTRACT

The interaction properties between natural fiber and matrix play an important role in the mechanical performance of composite materials. The adhesion properties and the mechanical interaction between an Ichu fiber (Stipa obtusa) treated with sodium hydroxide and a cementitious matrix were studied by conducting experimental, numerical, and analytical pull-out tests. Through the experimental tests, the force–displacement curve for a fiber length embedded 5 mm deep in the cementitious matrix, maximum force, cohesive parameters, and the type of interface failure were determined. The results were used to calibrate the numerical and analytical models for different lengths of fiber (3, 5, 7, 9, and 11 mm) embedded in the cementitious matrix. The numerical model was implemented in the finite element software Abaqus CAE, and the analytical formulation considered the fiber embedded in a half-space continuous medium. From the experimental test, the force–displacement curve, interfacial shear strength of 0.124 MPa, and the softening type slip were obtained, despite obtaining the hardening-type slip in certain tests. The numerical and analytical results of the load–displacement curve closely approximate the experimental results. This study provides a numerical and analytical model to simulate the alkali-treated Ichu fiber–cementitous matrix interface.

抽象的

天然纤维与基体的相互作用性能对复合材料的力学性能起着重要的作用. 通过实验, 数值和分析拔出试验, 研究了氢氧化钠处理的Ichu纤维 (针茅) 与水泥基基体之间的粘附性能和机械相互作用. 通过实验测试, 确定了嵌入水泥基中5mm深的纤维长度的力-位移曲线, 最大力, 粘结参数和界面破坏类型. 这些结果用于校准嵌入水泥基中不同长度纤维 (3, 5, 7, 9和11mm) 的数值和分析模型. 数值模型在有限元软件Abaqus CAE中实现, 分析公式考虑了纤维嵌入半空间连续介质. 尽管在某些试验中获得了硬化型滑移, 但从实验测试中获得了力-位移曲线, 0.124 MPa的界面剪切强度和软化型滑移. 荷载-位移曲线的数值和分析结果与实验结果非常接近. 本研究为模拟碱处理Ichu纤维-水泥基界面提供了一个数值和分析模型.

KEYWORDS:

• Natural fiber
• Ichu
• cementitious matrix
• pull-out
• cohesive properties
• mechanical properties

关键词:

• 天然纤维
• 胶结基质
• 拉出
• 粘结性能
• 机械性能

Highlights

• The adhesion properties and the mechanical interaction between an alkali-treated Ichu fiber (Stipa obtusa) and a cementitious matrix were studied.

• Through experimental tests, the force–displacement curve for a fiber length embedded 5 mm deep in cementitious matrix was obtained.

• Numerical and analytical pull-out tests were conducted for different fiber lengths (3, 5, 7, 9, and 11 mm).

• Numerical and analytical results of the load–displacement curve closely approximate the experimental results.

Acknowledgments

This paper was written in the context of the Project, “Production of fiber cement panels using materials obtained from Peruvian endemic plants” funded by PROCIENCIA-CONCYTEC, under the contract number N° 103-2018-FONDECYT-BM-IADT-MU. The authors of this paper appreciate the financial support from the Peruvian Government. We are also grateful to Carlos Tenazoa for his invaluable contribution in the experimental tests.

Disclosure statement

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

Additional information

Funding

This work was supported by the Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica [N° 103-2018-FONDECYT-BM-IADT-MU].