Abstract

Animal fibers with α-keratin had obvious advantages of mechanical strength and durability on reinforced microbially induced carbonate precipitation (MICP)-cemented loose sands. Herein, wool fiber, α-keratin-rich animal fiber with high strength, was applied to reinforcement of MICP-cemented loose sands. The mechanical properties and underlying mechanism were experimentally explored. Results showed that adding 0.1 wt% wool fiber enhanced up to 3.34-fold the compressive strength and significantly improved the flexure resistance performance. The microstructural results revealed that wool fibers providing many nucleation sites for calcite precipitation not only significantly decreased the porosity of the specimen, but also effectively generated calcite and distributed fiber-bridging microstructure uniformly, resulting in a marked reinforcement of MICP performance. Further studies indicated that sand grains were cemented with calcite through the intermolecular hydrogen bonds HN–H^…O–C(Si). This study first reports the potential and the underlying mechanism of animal fiber on improvement of MICP performance and provides new insight into enhancing mechanical behavior of MICP-cemented loose sands with fibrous proteins.

Graphic abstract

中文翻译：

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羊毛纤维对微生物诱导碳酸盐沉淀（MICP）加固松散砂的影响：力学性能和潜在机理

摘要

具有α-角蛋白的动物纤维在增强的微生物诱导的碳酸盐沉淀（MICP）胶结的疏松砂土上具有明显的机械强度和耐久性优势。在此，将羊毛纤维，具有高强度的富含α-角蛋白的动物纤维用于增强MICP胶结的散砂。实验研究了机械性能和潜在机理。结果表明，添加0.1 wt％的羊毛纤维可将抗压强度提高多达3.34倍，并显着提高了抗挠性能。显微组织结果表明，羊毛纤维为方解石沉淀提供了许多成核点，不仅显着降低了试样的孔隙率，而且还有效地生成了方解石并均匀地分布了纤维桥接的微结构。导致MICP性能显着增强。进一步的研究表明，沙粒通过分子间氢键HN–H与方解石胶结。^… OC（Si）。这项研究首先报告了动物纤维在改善MICP性能方面的潜力及其潜在机理，并为增强纤维蛋白对MICP胶结疏松砂土的力学行为提供了新的见解。

图形摘要