Zhang Xiaoxiao, Pel Leo, Gauvin Florent, Smeulders David
Department of Applied Physics, Transport in Permeable Media, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Department of Built Environment, Building Materials, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Materials (Basel). 2021 Feb 2;14(3):699. doi: 10.3390/ma14030699.
Due to the requirement for developing more sustainable constructions, natural fibers from agricultural wastes, such as coir fibers, have been increasingly used as an alternative in concrete composites. However, the influence of coir fibers on the hydration and shrinkage of cement-based materials is not clear. In addition, limited information about the reinforcing mechanisms of coir fibers in concrete can be found. The goal of this research is to investigate the effects of coir fibers on the hydration reaction, microstructure, shrinkages, and mechanical properties of cement-based light-weight aggregate concrete (LWAC). Treatments on coir fibers, namely Ca(OH) and nano-silica impregnation, are applied to further improve LWAC. Results show that leachates from fibers acting as a delayed accelerator promote cement hydration, and entrained water by fibers facilitates cement hydration during the whole process. The drying shrinkage of LWAC is increased by adding fibers, while the autogenous shrinkage decreases. The strength and toughness of LWAC are enhanced with fibers. Finally, three reinforcement mechanisms of coir fibers in cement composites are discussed.
由于对开发更可持续建筑的需求，来自农业废弃物的天然纤维，如椰壳纤维，已越来越多地被用作混凝土复合材料的替代品。然而，椰壳纤维对水泥基材料水化和收缩的影响尚不清楚。此外，关于椰壳纤维在混凝土中的增强机理的信息有限。本研究的目的是研究椰壳纤维对水泥基轻骨料混凝土（LWAC）的水化反应、微观结构、收缩和力学性能的影响。对椰壳纤维进行了处理，即氢氧化钙（Ca(OH)）和纳米二氧化硅浸渍处理，以进一步改善LWAC。结果表明，纤维沥出物作为缓凝促进剂促进水泥水化，纤维夹带的水分在整个过程中促进水泥水化。添加纤维会增加LWAC的干燥收缩，而自收缩则会减小。纤维增强了LWAC的强度和韧性。最后，讨论了椰壳纤维在水泥复合材料中的三种增强机理。
