New processes and applications for waste generated in forestry and mineral activities favor the circular economy and reduce pressure on conventional raw materials, thus promoting the sustainability of activities. This research aimed to apply quartzite powder to replace limestone and fibers and cellulosic micro/nanofibrils (MFC/NFC) from as reinforcement in extruded fiber-cement. To improve fiber/matrix compatibility, some fiber treatments with NaOH and Aℓ(SO) + CHO were also evaluated. The fiber cements were produced by an extrusion process using a formulation of 66.5 % of CPV-ARI Portland cement, 28.5 % of quartzite powder and 5 % of fiber reinforcement. The physical (apparent density, water absorption, and porosity), mechanical properties (modulus of rupture, modulus of elasticity, limit of proportionality, and toughness), thermal conductivity, and microstructural properties of the fiber-cements were evaluated after 28 days of curing. Treatments with 5 % fibers exhibited better mechanical performances. It was possible to improve the microstructure and physical-mechanical performance of the composites using small amounts of MFC/NFC (0.5 %). Quartzite positively affected the properties and provided thermal comfort (∼0.11 W/mK). Therefore, the materials showed promise for producing extruded fiber-cement composites.

中文翻译：

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巴西橡胶树纤维矿化对纤维素微/纳米原纤维 (MFC/NFC) 和石英岩残留物挤压纤维水泥生产的影响


林业和矿产活动中产生的废物的新工艺和应用有利于循环经济，减少对传统原材料的压力，从而促进活动的可持续性。本研究旨在应用石英岩粉末代替石灰石以及纤维和纤维素微/纳米原纤维（MFC/NFC）作为挤压纤维水泥中的增强材料。为了改善纤维/基体相容性，还评估了一些用 NaOH 和 Aℓ(SO) + CHO 处理的纤维。纤维水泥采用挤压工艺生产，配方为 66.5% CPV-ARI 波特兰水泥、28.5% 石英岩粉末和 5% 纤维增强材料。固化 28 天后，评估纤维水泥的物理（表观密度、吸水率和孔隙率）、机械性能（断裂模量、弹性模量、比例极限和韧性）、导热系数和微观结构性能。用 5% 纤维处理表现出更好的机械性能。使用少量 MFC/NFC (0.5%) 可以改善复合材料的微观结构和物理机械性能。石英岩对性能产生积极影响并提供热舒适性（∼0.11 W/mK）。因此，这些材料显示出生产挤压纤维水泥复合材料的前景。