Magnesium phosphate cement (MPC) is the preferred material for rapid repair due to its rapid setting and early strength properties. However, its inherent brittleness renders it less suitable for use in assembled building nodes. To address the brittleness of MPC, coconut fiber (CF), a natural fiber known for its toughness, is often employed as a reinforcement. However, CF-MPC encounter difficulties in high-temperature settings, such as fire emergencies, which may compromise the interfacial bonding properties of this materials. This paper presents an investigation into the interfacial bonding properties of CF-MPC at elevated temperatures. The study employed microscopic analysis to observe the material changes of CF at elevated temperatures, evaluated the mechanical property changes by means of Fiber Tensile Test, and assessed the interfacial bonding performance by means of Fiber Drawing Test between CF and MPC. The findings indicated that as the temperature increased, the carbonized residue of the CF gradually decomposed, resulting in a notable decline in mechanical strength. Upon exceeding 400 °C, the carbonization of CF was complete, resulting in the loss of its mechanical properties. Besides the results also demonstrated that the interfacial bond strength of CF-MPC at a burial depth of 7.5 mm reaches its maximum value of 2.14 MPa at 20 °C. As the temperature rises to 200 °C, the interfacial bond strength at a burial depth of 12.5 mm reaches its maximum value of 1.08 MPa at this temperature. The findings of this study are conducive to promoting the application of CF-MPC at high temperatures and provide a theoretical basis for the subsequent optimization of this material.

中文翻译：

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高温对再生椰子纤维增强水泥复合材料界面粘结性能的影响


磷酸镁水泥 （MPC） 因其快速凝固和早期强度特性而成为快速修复的首选材料。然而，其固有的脆性使其不太适合用于组装式建筑节点。为了解决 MPC 的脆性问题，椰子纤维 （CF） 是一种以其韧性而闻名的天然纤维，通常被用作增强材料。然而，CF-MPC 在高温环境中遇到困难，例如火灾紧急情况，这可能会损害这种材料的界面粘合性能。本文研究了 CF-MPC 在高温下的界面键合性能。该研究采用显微分析观察 CF 在高温下的材料变化，通过纤维拉伸试验评估机械性能变化，并通过 CF 和 MPC 之间的纤维拉丝测试评估界面粘合性能。结果表明，随着温度的升高，CF 的碳化残渣逐渐分解，导致机械强度显着下降。超过 400 °C 时，CF 的碳化完全，导致其机械性能丧失。此外，结果还表明，CF-MPC 在 7.5 mm 埋深处的界面粘合强度在 20 °C 时达到最大值 2.14 MPa。 当温度升高到 200 °C 时，埋深为 12.5 mm 的界面粘合强度在此温度下达到最大值 1.08 MPa。本研究结果有利于促进 CF-MPC 在高温下的应用，并为该材料的后续优化提供理论依据。