Ding Hongjian, Sun Quansheng, Wang Yanqi, Jia Dongzhe, Li Chunwei, Ji Ce, Feng Yuping
College of Civil Engineering, Northeast Forestry University, Harbin 150040, China.
Material Science and Engineering College, Northeast Forestry University, Harbin 150040, China.
Materials (Basel). 2021 Sep 19;14(18):5421. doi: 10.3390/ma14185421.
In view of the problems of traditional repair materials for anchorage concrete of expansion joints, such as ease of damage and long maintenance cycles, the design of polyurethane concrete was optimized in this article, which could be used for rapid repair of concrete in anchorage zone of expansion joints. A new type of carbon fiber grid-polyurethane concrete system was designed, which makes the carbon fiber grid have an excellent synergistic effect with the quick-hardening and high-strength polyurethane concrete, and improved the flexural bearing capacity of the polyurethane concrete. Through the four-point bending test, the influence of the parameters such as the number of grid layers, grid width, and grid density on the flexural bearing capacity of polyurethane concrete beams was tested. The optimum preparation process parameters of carbon fiber grid were obtained to improve the flexural performance of polyurethane concrete. Compared with the Normal specimen, C-80-1's average flexural strength increased by 47.7%, the failure strain along the beam height increased by 431.1%, and the failure strain at the bottom of the beam increased by 68.9%. The best width of the carbon fiber grid was 80 mm, and the best number of reinforcement layers was one layer. The test results show that the carbon fiber grid could improve the flexural bearing capacity of polyurethane concrete. The carbon fiber grid-polyurethane concrete system provides a new idea for rapid repair of the anchorage zone of bridge expansion joints, and solves the problems such as ease of damage and long maintenance cycles of traditional repair materials, which can be widely used in the future.
针对伸缩缝锚固混凝土传统修补材料易损坏、维修周期长等问题，本文对可用于伸缩缝锚固区混凝土快速修补的聚氨酯混凝土进行了优化设计。设计了一种新型碳纤维格栅-聚氨酯混凝土体系，使碳纤维格栅与快硬高强的聚氨酯混凝土产生良好的协同效应，提高了聚氨酯混凝土的抗弯承载能力。通过四点弯曲试验，测试了格栅层数、格栅宽度、格栅密度等参数对聚氨酯混凝土梁抗弯承载能力的影响。得出了碳纤维格栅的最佳制备工艺参数，以提高聚氨酯混凝土的抗弯性能。与普通试件相比，C-80-1的平均抗弯强度提高了47.7%，沿梁高的破坏应变提高了431.1%，梁底部的破坏应变提高了68.9%。碳纤维格栅的最佳宽度为80mm，最佳加固层数为一层。试验结果表明，碳纤维格栅可提高聚氨酯混凝土的抗弯承载能力。碳纤维格栅-聚氨酯混凝土体系为桥梁伸缩缝锚固区的快速修补提供了新思路，解决了传统修补材料易损坏、维修周期长等问题，具有广阔的应用前景。
