State Key Laboratory of Fire Science, USTC, Hefei, 230027, PR China.
J Hazard Mater. 2010 Jul 15;179(1-3):373-81. doi: 10.1016/j.jhazmat.2010.03.015. Epub 2010 Mar 10.
The objective of the present study is to analyze the fire protection properties of old and new cables through TG, FTIR and MCC experiments. The results show that the mass loss of old cable sheath is clearly larger than the new one when the temperature is higher than 550 K in air or nitrogen atmosphere. It suggests that the old cable sheath starts to pyrolyze generally at the same temperature based on the analysis of the onset temperatures of mass loss. The results also show that there is a main peak DTG for the old and new cable sheath under each condition. However, the main peak DTG of old cable sheath is larger than that of the new cable sheath, especially in air atmosphere. The FTIR experiments show that the HCl is released by the new cable later but more quickly than the old cable. The MCC experiments suggest that compared with the new one, the peak heat release rate is larger for the old cable. It illustrates that the old cable sheath generally pyrolyzes and combusts more strongly and completely than the new one. Namely, the fire protection properties of the old cable in old buildings are relatively weak.
本研究的目的是通过 TG、FTIR 和 MCC 实验分析新旧电缆的防火性能。结果表明，在空气或氮气气氛中，当温度高于 550K 时，旧电缆护套的质量损失明显大于新电缆护套。这表明，基于起始质量损失温度的分析，旧电缆护套通常在相同的温度下开始热解。结果还表明，在每种情况下，新旧电缆护套都有一个主要的 DTG 峰。然而，旧电缆护套的主要 DTG 峰大于新电缆护套的主要 DTG 峰，尤其是在空气气氛中。FTIR 实验表明，新电缆比旧电缆释放 HCl 的时间晚，但速度更快。MCC 实验表明，与新电缆相比，旧电缆的峰值放热率更大。这说明旧电缆护套通常比新电缆护套更强烈、更完全地热解和燃烧。也就是说，旧建筑物中旧电缆的防火性能相对较弱。
