Liu Yiwen, Su Bo, Zhang Tianyu
Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212000, China.
Polymers (Basel). 2024 Nov 27;16(23):3327. doi: 10.3390/polym16233327.
Glass Fiber-Reinforced Composite (GFRP) has found widespread use in engineering structures due to its lightweight construction, high strength, and design flexibility. However, pure GFRP beams exhibit weaknesses in terms of stiffness, stability, and local compressive strength, which compromise their bending properties. In addressing these limitations, this study introduces innovative square GFRP beams infused with gypsum-based composites (GBIGCs). Comprehensive experiments and theoretical analyses have been conducted to explore their manufacturing process and bending characteristics. Initially, four types of GBIGC-namely, hollow GFRP beams, pure gypsum, steel-reinforced gypsum, and fiber-mixed gypsum-infused beams-were designed and fabricated for comparative analysis. Material tests were conducted to assess the coagulation characteristics of gypsum and its mechanical performance influenced by polyvinyl acetate fibers (PVAs). Subsequently, eight GFRP square beams (length: 1.5 m, section size: 150 mm × 150 mm) infused with different gypsum-based composites underwent four-point bending tests to determine their ultimate bending capacity and deflection patterns. The findings revealed that a 0.12% dosage of protein retarder effectively extends the coagulation time of gypsum, making it suitable for specimen preparation, with initial and final setting times of 113 min and 135 min, respectively. The ultimate bending load of PVA-mixed gypsum-infused GFRP beams is 203.84% higher than that of hollow beams, followed by pure gypsum and steel-reinforced gypsum, with increased values of 136.97% and 186.91%, respectively. The ultimate load values from the theoretical and experimental results showed good agreement, with an error within 7.68%. These three types of GBIGCs with significantly enhanced flexural performance can be filled with different materials to meet specific load-bearing requirements for various scenarios. Their improved flexural strength and lightweight characteristics make GBIGCs well suited for applications such as repairing roof beams, light prefabricated frames, coastal and offshore buildings.
玻璃纤维增强复合材料（GFRP）因其轻质结构、高强度和设计灵活性而在工程结构中得到广泛应用。然而，纯GFRP梁在刚度、稳定性和局部抗压强度方面存在弱点，这影响了它们的弯曲性能。为了解决这些局限性，本研究引入了注入石膏基复合材料（GBIGC）的创新方形GFRP梁。进行了全面的实验和理论分析，以探索其制造工艺和弯曲特性。首先，设计并制造了四种类型的GBIGC，即空心GFRP梁、纯石膏、钢筋石膏和纤维混合石膏注入梁，用于对比分析。进行了材料测试，以评估石膏的凝结特性及其受聚醋酸乙烯酯纤维（PVA）影响的力学性能。随后，对八根注入不同石膏基复合材料的GFRP方形梁（长度：1.5米，截面尺寸：150毫米×150毫米）进行了四点弯曲试验，以确定其极限弯曲能力和挠度模式。研究结果表明，0.12%剂量的缓凝剂能有效延长石膏的凝结时间，使其适合制备试件，初凝和终凝时间分别为113分钟和135分钟。注入PVA混合石膏的GFRP梁的极限弯曲荷载比空心梁高203.84%，其次是纯石膏和钢筋石膏，增加值分别为136.97%和186.91%。理论和实验结果的极限荷载值吻合良好，误差在7.68%以内。这三种抗弯性能显著增强的GBIGC可以填充不同材料，以满足各种场景下的特定承载要求。它们提高的抗弯强度和轻质特性使GBIGC非常适合用于修复屋顶梁、轻型预制框架、沿海和近海建筑等应用。
