Luo Liquan, Shi Benkai, Liu Weiqing, Yang Huifeng, Ling Zhibin
College of Civil Engineering, Nanjing Tech University, Nanjing 211816, China.
School of Civil Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2020 Jun 16;13(12):2731. doi: 10.3390/ma13122731.
This paper presents an experimental evaluation of the fire resistance of glued-in rod timber joints using epoxy resin, with and without modification. A heat-resistant modified resin was designed by adding inorganic additives into the epoxy resin, aiming to improve the heat resistance. Joints that were made using the modified epoxy resin at room temperature showed a bearing capacity comparable to those with commercial epoxy resin. Twenty-one joint specimens with the modified epoxy resin and six with a commercial epoxy resin were tested in a fire furnace to evaluate the fire resistance. The main failure mode was the pull-out of the rod, which is typical in fire tests of this type of joints. As to the effects of the test parameters, this study considered the effects of adhesive types, sectional sizes, stress levels, and fireproof coatings. The test results showed that the fire resistance period of a joint can be evidently improved by modifying the resin and using the fireproof coating, as the improvements reached 73% and 35%, respectively, compared with the joint specimens with commercial epoxy resin. It was also found that, for all specimens, the fire resistance period decreased with an increase in the stress level and increased with an increase in the sectional sizes.
本文介绍了使用环氧树脂的植入式杆木材接头在有或无改性情况下的耐火性能实验评估。通过在环氧树脂中添加无机添加剂设计了一种耐热改性树脂，旨在提高耐热性。在室温下使用改性环氧树脂制成的接头显示出与使用商用环氧树脂制成的接头相当的承载能力。对21个使用改性环氧树脂的接头试件和6个使用商用环氧树脂的接头试件在火炉中进行测试，以评估其耐火性能。主要失效模式是杆的拔出，这在这类接头的火灾试验中很典型。至于试验参数的影响，本研究考虑了胶粘剂类型、截面尺寸、应力水平和防火涂层的影响。试验结果表明，通过改性树脂和使用防火涂层，接头的耐火期可得到显著提高，与使用商用环氧树脂的接头试件相比，提高幅度分别达到73%和35%。还发现，对于所有试件，耐火期随应力水平的增加而降低，随截面尺寸的增加而增加。
