This work presents the influence of the wetting and drying cycles on the tensile behavior of the strain-hardening cement-based composites reinforced with natural curauá fiber. The 3 sets of 10 dog bone shape specimens were prepared and submitted to the cycles. After 15, 30 and 45 cycles the composites were tested under tensile load in wet (5 specimens) and dry conditions (5 specimens) and compared to the reference specimens. After the cycles, composites presented strain-softening behavior. The residual fiber stress and strain at rupture were verified on fibers extracted from the composites submitted to the tensile test. This procedure was applied to the determination of the matrix environment influence on fiber properties after accelerated aging cycles. The strain-softening behavior of the composites submitted to the wetting and drying cycles was correlated with the fiber-matrix interfacial observations under a microscope and highlighted by fiber pull-out work indicators. The strain-softening behavior is strongly related to the natural fiber volume change and defibrillation induced by the moisture movement during aging.

中文翻译：

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水分运动对碱处理过的柑桔纤维 SHCC 拉伸应力-应变行为的影响

这项工作展示了润湿循环和干燥循环对用天然库拉阿纤维增强的应变硬化水泥基复合材料的拉伸行为的影响。制备了 3 组 10 个狗骨形状样本并提交给循环。在 15、30 和 45 次循环后，复合材料在湿（5 个试样）和干燥条件（5 个试样）的拉伸载荷下进行测试，并与参考试样进行比较。循环后，复合材料呈现应变软化行为。对从复合材料中提取的纤维进行拉伸试验，验证了断裂时的残余纤维应力和应变。该程序用于确定加速老化循环后基体环境对纤维性能的影响。经受润湿和干燥循环的复合材料的应变软化行为与显微镜下的纤维-基质界面观察相关，并通过纤维拉出功指标突出显示。应变软化行为与老化过程中水分运动引起的天然纤维体积变化和去纤颤密切相关。