Partnership for Advancing Technologies in Housing: An Integrated Program to Examine the Moisture-related Performance of Fiber-cement Composites

路径：检查纤维水泥复合材料与水分相关性能的综合计划湿/干循环对纤维水泥复合材料的影响以及由此产生的损坏机制尚未成为广泛系统检查的主题。这种基础知识的缺乏限制了我们准确预测纤维水泥材料使用寿命的能力，以及我们选择纤维水泥复合材料材料的能力，这些材料有望在预期湿度波动的情况下表现出良好的性能。 一个全面的研究计划是必要的，以充分了解纤维膨胀/收缩对纤维水泥复合材料系统的影响-发生在纤维，周围的脆性基质，以及作为一个整体的复合材料的性能的变化。综合研究项目的目标是由土木工程的混凝土技术专家和造纸科学与技术的造纸物理学家组成的研究小组进行，将由于周期性水分变化而在微观结构水平上发生的变化与纤维水泥复合材料宏观力学性能的变化联系起来。拟议研究的目标是（1）评估反复润湿和干燥（雨和热）循环对木纤维尺寸变化的影响，纤维/水泥浆界面的物理粘合，以及纤维和基质之间的粘合强度和（2）评估是否可以通过定制纤维加工来改善粘合。该提案包括准备特殊的对齐纤维水泥复合材料，将提供定性和定量微观结构分析的机会。

PATH: An Integrated Program to Examine the Moisture-related Performance of Fiber-cement CompositesThe effect of wet/dry cycling on fiber-cement composites and the resulting mechanisms of damage have not been the subject of an extensive systematic examination. This lack of fundamental knowledge limits our ability to accurately predict service lives of fiber-cement materials and our ability to select materials for fiber-cement composites which are expected to exhibit good performance in exposures where moisture fluctuations are expected. A comprehensive research plan is necessary to fully understand the implications of fiber swelling/shrinking on the fiber-cement composite system - the changes that occur in the fiber, surrounding brittle matrix, and the performance of the composite as a whole. The objective of the integrated research project, to be undertaken by a research team composed of concrete technologists from Civil Engineering and paper physicists from Paper Science and Technology, is to link changes that occur on a microstructural level as a result of cyclical moisture changes to the changes in macroscale mechanical properties of the fiber-cement composite. The goals of the proposed research are (1) to assess the effects of repeated wetting and drying (rain and heat) cycles on dimensional changes of wood fibers, physical bonding at the fiber/cement paste interface, and bond strength between the fiber and matrix and (2) to assess if improved bonding can be produced through tailoring the fiber processing for this application. The proposal includes preparation of special aligned fiber cement-composites that will offer improved opportunities for both qualitative and quantitative microstructural analysis.