Tan Lixin, Yang Jun, Li Chuanxi, Zhang Gaozhan, Ding Qingjun, Sun Daosheng, Zhang Yongyuan
School of Civil Engineering, Changsha University of Science & Technology, No. 960, SEC. 2, Wanjiali South Road, Yuhua District, Changsha 410114, China.
Poly Changda Co., Ltd., No. 942, Guangzhou Avenue, Tianhe District, Guangzhou 510640, China.
Materials (Basel). 2023 Nov 2;16(21):7014. doi: 10.3390/ma16217014.
It is necessary to prepare marine UHPC with synthetic fibers instead of steel fibers, owing to the corrosion risk of steel fibers in marine environments. Currently, the performance of UHPC prepared with different types of fibers has not been comparatively investigated. This work prepared UHPC with steel fiber, polyoxymethylene (POM) fiber, polypropylene (PP) fiber, and polyvinyl alcohol (PVA) fiber. The effects of different fibers on the mechanical properties, impact, and abrasion resistance of UHPC were studied and compared. The results showed that increasing POM fiber can increase the mechanical strength, flexural toughness, impact, and abrasion resistance of UHPC. When its content reaches 2%, the adsorbed-in-fracture energy and abrasion strength of UHPC are 2670 J and 105 h/(kg/m), respectively. At the same fiber content, POM fiber-reinforced UHPC shows better mechanical strength, toughness, and impact- and abrasion-resistance than the polypropylene (PP)- and polyvinyl alcohol (PVA)-fiber-reinforced UHPCs. Microstructure investigation found that PP fiber has the weakest binding with UHPC paste, which would directly pull out of the matrix under external tensile loading. This weak connection limits the strengthening and toughening effect on the UHPC. PVA fiber has an excellent interfacial connection with the UHPC paste. However, the low tensile strength of PVA fiber limits the strength and toughness of UHPC. POM fiber has a high tensile strength and can absorb tensile loading through debonding, fracture, and tearing. The fracture interface of POM fiber is large, indicating its significant role in strengthening and toughening the UHPC.
由于钢纤维在海洋环境中存在腐蚀风险，因此有必要用合成纤维而非钢纤维来制备海洋超高性能混凝土（UHPC）。目前，对于用不同类型纤维制备的UHPC的性能尚未进行比较研究。本研究用钢纤维、聚甲醛（POM）纤维、聚丙烯（PP）纤维和聚乙烯醇（PVA）纤维制备了UHPC。研究并比较了不同纤维对UHPC力学性能、抗冲击性和耐磨性的影响。结果表明，增加POM纤维可以提高UHPC的机械强度、弯曲韧性、抗冲击性和耐磨性。当其含量达到2%时，UHPC的断裂吸附能和耐磨强度分别为2670 J和105 h/(kg/m)。在相同纤维含量下，POM纤维增强的UHPC比聚丙烯（PP）纤维和聚乙烯醇（PVA）纤维增强的UHPC表现出更好的机械强度、韧性以及抗冲击和耐磨性能。微观结构研究发现，PP纤维与UHPC浆体的结合最弱，在外部拉伸载荷下会直接从基体中拔出。这种弱连接限制了对UHPC的增强增韧效果。PVA纤维与UHPC浆体具有优异的界面连接。然而，PVA纤维的低拉伸强度限制了UHPC的强度和韧性。POM纤维具有较高的拉伸强度，可通过脱粘、断裂和撕裂吸收拉伸载荷。POM纤维的断裂界面较大，表明其在增强增韧UHPC方面具有重要作用。
