碳纳米管对超高性能混凝土化物扩散,强度和微观结构的影响
Mahdi Rafieizonooz1, Jang-Ho Jay Kim1, Jin-Su Kim1
1School of Civil and Environmental Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea.
Materials (Basel, Switzerland)
|June 27, 2024
概括
这项研究研究了超高性能混凝土 (UHPC) 中的碳纳米管 (CNT),发现最佳度可以提高强度和耐用性. 较低的CNT水平提高了性能,而较高的水平降低了压力强度.
科学领域:
- 材料科学 材料科学 材料科学
- 土木工程 土木工程是指土木工程.
- 纳米技术 纳米技术
背景情况:
- 超高性能混凝土 (UHPC) 具有优越的机械性能,但可能很密,容易受到化物入.
- 碳纳米管 (CNTs) 被探索为纳米级的添加剂,以提高混凝土的性能.
- 人工轻质聚合物 (ALA) 和微空心球 (MHS) 用于降低UHPC密度,并可能改善机械特性.
研究的目的:
- 评估不同碳纳米管 (CNT) 度对超高性能混凝土 (UHPC) 机械性能,微观结构和耐久性的影响.
- 评估CNT与轻质聚合物的结合对化物透的影响,并预测修改后的HHPC的使用寿命.
- 确定最佳的CNT含量,以提高UHPC应用中的性能.
主要方法:
- 用分散的CNT溶液 (0.025-0.075重量%) 和可流动性的超塑剂制备UHPC混合物.
- 用人工轻质聚合物 (ALA) 和微型空洞球体 (MHS) 组合替换精细聚合物,以减少重量和增强机械性能.
- 机械性能测试 (压力强度),用于微观结构分析的扫描电子显微镜 (SEM),加速化物透测试和寿命预测.
主要成果:
- 压缩强度在0.025%和0.05%的CNT度 (CNT1,CNT2) 略有改善,但在0.075% (CNT3) 降低.
- 在更高的CNT度下,SEM分析显示在混凝土矩阵内形成纳米级桥梁.
- 所有测试的混合物均表现出低于标准限值 (1.00 × 10-12 m2 / s) 的有效化物输送系数.
- 寿命服务预测表明,CNT1和CNT2混合物在各种环境条件下表现优越.
结论:
- 最佳的CNT度 (0.025-0.05%) 可以提高UHPC的压力强度和耐久性,当与ALA和MHS结合使用时.
- 较高的CNT度可能会对压力强度产生负面影响,原因是聚合物或矩阵破坏.
- 经过修改的UHPC表现出极好的抗化物透性,并提供有前途的延长使用寿命,特别是在优化CNT含量的情况下.
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