硼酸锌对隧道阻燃沥青的阻燃增效作用及机理

Synergistic Effect of Zinc Borate on Tunnel Flame-Retardant Asphalt and Its Mechanism

利用硼酸锌(ZB)与自制的沥青阻燃剂(BFR-Si)对道路沥青进行复合改性来制备隧道阻燃沥青.通过锥形量热法、热重分析法和烟密度法等测试方法系统研究了ZB与BFR-Si协同阻燃道路沥青的燃烧性能,探究了二者的阻燃增效作用和阻燃机理.结果表明:添加适量ZB可使道路沥青+BFR-Si体系的烟密度(Ds)、热释放速率(HRR)、质量损失速率(MLR)以及有效燃烧热(EHC)等指标显著下降,点燃时间显著延长,实际成炭量增加;ZB对道路沥青+BFR-Si体系具有较显著的阻燃增效作用;道路沥青+BFR-Si体系呈现吸热阻燃机理和凝聚相阻燃机理的特征,道路沥青+BFR-Si+ZB体系主要呈现凝聚相阻燃机理的特征.

Tunnel flame-retardant asphalt was prepared by zinc borate（ZB）and self-made flame retardant（BFRSi）,and its combustion performances were systematically investigated through cone calorimetry,thermal gravimetric analysis and smoke density analysis methods.The synergistic effect of BFR-Si and ZB was discussed.The results indicate that ZB and BFR-Si have synergistic effect which made the smoke density（Ds）,the heat release rate（HRR）,mass loss rate（MLR）and the effective heat of combustion（EHC）indicators of road asphalt＋BFR-Si system decrease,while the ignition time become longer and the practical carbon content increases,that is to say the flame resistance performance of the flame-retardant asphalt is significantly improved.Road asphalt＋BFR-Si system shows endothermic flame retardant mechanism and condensed phase flame retardant character,while road asphalt＋BFR-Si＋ZB system shows the condensed phase flame-retardant mechanism mainly.