Wu Chuan
Chongqing Industry Polytechnic College, Chongqing, 401120, People's Republic of China.
Sci Rep. 2024 Jul 24;14(1):17105. doi: 10.1038/s41598-024-67137-z.
To explore the effect and mechanism of coir fiber on the performance of foamed concrete, the flexural performance test, pore characteristics and microstructure test of coir fiber foamed concrete with different content were carried out. First, Image-Pro Plus (image processing software) was used to study the pore morphology, porosity, average pore diameter, and pore roundness of CFFC with various fibers dosage (0, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%) by binarization processing method. Then, a total of eighteen specimens, divided into six groups, were used to investigate the effect of CF dosage on flexural strength, toughness, energy absorption, and failure patterns of FC through a three-point flexural test. Furthermore, the microscopic properties of coir fiber foamed concrete (CFFC) were observed by scanning electron microscope (SEM) and energy dispersive X-ray detector (XRD) to explain the influence mechanism of CF on FC flexural properties. According to the research, CF can affect the pore characteristics of CFFC and improve its flexural performance. When CF content is 1.5-2.0%, the porosity, diameter and roundness of CFFC have lower values of 68.6%, 1.96 mm and 1.29. After the fiber dosage reaches 1.5%, the CFFC failure mode changed to plastic damage, the flexural strength increased from 0.33 to 0.73 MPa, and the toughness energy absorption value was increased from 0.05 to 1.4 J. The optimum dosage of coir fiber is 2.0% for improving the flexural mechanical properties of FC. CF affects the process of hydration reaction of CFFC, but does not change the type of hydration product. However, the flexural performance of FC would decrease with excessive dosage of CF (> 2.0%) due to accelerating the formation of Ca(OH). CFFC can solve problems such as brittleness and easy cracking existing in traditional foamed concrete, and it can be used in the field of pavement engineering, foundation backfill and lightweight wall structure with CF dosage of 15-2.0%.
为探究椰壳纤维对泡沫混凝土性能的影响及作用机制，对不同含量的椰壳纤维泡沫混凝土进行了抗折性能试验、孔隙特征及微观结构试验。首先，采用Image-Pro Plus（图像处理软件）通过二值化处理方法研究了不同纤维掺量（0、0.5%、1.0%、1.5%、2.0%、2.5%）的椰壳纤维泡沫混凝土（CFFC）的孔隙形态、孔隙率、平均孔径和孔隙圆度。然后，总共制作了18个试件，分为6组，通过三点弯曲试验研究椰壳纤维掺量对泡沫混凝土（FC）抗折强度、韧性、能量吸收和破坏模式的影响。此外，通过扫描电子显微镜（SEM）和能量色散X射线探测器（XRD）观察椰壳纤维泡沫混凝土（CFFC）的微观特性，以解释椰壳纤维对泡沫混凝土抗折性能的影响机制。研究表明，椰壳纤维会影响CFFC的孔隙特征并改善其抗折性能。当椰壳纤维含量为1.5 - 2.0%时，CFFC的孔隙率、孔径和圆度较低，分别为68.6%、1.96毫米和1.29。当纤维掺量达到1.5%后，CFFC的破坏模式转变为塑性破坏，抗折强度从0.33兆帕提高到0.73兆帕，韧性能量吸收值从0.05焦耳提高到1.4焦耳。提高泡沫混凝土抗折力学性能的椰壳纤维最佳掺量为2.0%。椰壳纤维影响CFFC的水化反应过程，但不改变水化产物类型。然而，由于加速了Ca(OH)₂的生成，当椰壳纤维掺量过多（>2.0%）时，泡沫混凝土的抗折性能会下降。当椰壳纤维掺量为1.5 - 2.0%时，CFFC可解决传统泡沫混凝土存在的脆性和易开裂等问题，可用于路面工程、地基回填和轻质墙体结构领域。
