Liu Jin, Chen Zhihao, Song Zezhuo, Bai Yuxia, Qian Wei, Wei Jihong, Kanungo Debi Prasanna
School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, China.
CSIR-Central Building Research Institute (CBRI), Roorkee 247667, India.
Polymers (Basel). 2018 May 4;10(5):499. doi: 10.3390/polym10050499.
Physical and chemical reinforcements are commonly used to improve sand properties for engineering requirements. Many researchers have concluded that composite reinforcement can greatly improve sand property strength. In this paper, polyurethane organic polymer (PU) and polypropylene fiber (PF) were used to reinforce sand. It is found that composite reinforcement has great effects on tensile strength. A series of direct tensile tests were conducted to demonstrate this reinforcement and to investigate the effects of PF content, PU content, dry density, and curing time. Additionally, the reinforcement mechanism was analyzed by scanning electron microscope images. The tensile strength increases with curing time until it reaches a plateau. The composite reinforcement improves the tensile strength exponentially with the increase of PF and PU contents. For the effect due to dry density, the tensile strength first increased and then decreased with the peak at approximately 1.55 g/cm³. Through the interaction force among fibers and sand particles and the bonding force of polymer among sand particles, tensile strength of reinforced sand is greatly improved.
物理和化学增强材料通常用于根据工程要求改善砂土性能。许多研究人员得出结论，复合增强材料可以大大提高砂土性能强度。在本文中，聚氨酯有机聚合物（PU）和聚丙烯纤维（PF）被用于增强砂土。研究发现，复合增强对拉伸强度有很大影响。进行了一系列直接拉伸试验以证明这种增强效果，并研究PF含量、PU含量、干密度和养护时间的影响。此外，通过扫描电子显微镜图像分析了增强机理。拉伸强度随养护时间增加，直至达到平稳状态。随着PF和PU含量的增加，复合增强呈指数级提高拉伸强度。对于干密度的影响，拉伸强度先增加后降低，峰值约为1.55 g/cm³。通过纤维与砂粒之间的相互作用力以及聚合物在砂粒之间的粘结力，增强砂土的拉伸强度得到了极大提高。
