消石灰对沥青阻燃性能的影响  

Hydrated lime modification of asphalt mixtures with improved fire performance

作　　者：朱凯[1,2] 黄志义[1] 吴珂[1] 武斌[1] 张欣[1] 张驰[1] 

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058 [2]中国计量学院质量与安全学院,浙江杭州310018

出　　处：《浙江大学学报（工学版）》2015年第5期963-968,共6页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51408542);浙江省自然科学基金资助项目(LY14E080014)

摘　　要：为了研究消石灰对沥青阻燃性能的影响,采用极限氧指数、锥形量热仪、热重-差热试验对消石灰改性沥青的燃烧特性进行表征,并与石灰石和氢氧化镁进行对比.试验结果表明,与添加等量石灰石相比,添加消石灰沥青的极限氧指数明显提高,与添加氢氧化镁接近;同时锥形量热仪实验表明消石灰可延长沥青点燃时间,有效降低沥青的燃尽率、燃烧反应速率、烟释放率和释热量,减少燃烧过程中CO的释放.与氢氧化镁不同,在反应初期消石灰并非利用吸热的分解反应起到阻燃作用,而是通过抑制可燃挥发分的析出,以延缓沥青的着火;同时,在沥青燃烧过程中消石灰会进一步发生碳酸化反应,形成致密的碳酸盐阻隔层,起到阻隔热质交换和抑制沥青质燃烧的作用.The effects of hydrated lime addition on flame retardancy of asphalt were investigated by means of limiting oxygen index （LOI）, cone calorimeter and thermal gravimetric-differential scanning calorimetric （TG-DSC） tests, the results of which were directly compared with limestone and magnesium hydroxide ad- ditions. Experimental results revealed that the addition of hydrated lime has significantly increased the LOI of asphalt, where this improvement is much higher than that of limestone addition but similar to that of Mg（OH）2 addition. Cone calorimeter tests further show that the hydrated lime addition could result in the reductions in burn-out rate, burning rate, heat release rate and smoke release rate of asphalt, whereas the release of CO is also inhibited. Unlike Mg（OH）2 addition, the hydrated lime does not proceed a decompo- sition process at the initial reaction stage to achieve flame retardancy but via suppressing the release of flammable volatile to prevent the asphalt from igniting. Moreover, during asphalt combustion, the hydrat- ed lime has further induced a carbonation reaction, generating a dense residue layer that suppresses the heat and mass transfer and hence inhibiting the combustion of asphaltenes.

关 键 词：沥青 阻燃性能 热重-差热 锥形量热仪 消石灰 

分 类 号：U416.217[交通运输工程—道路与铁道工程]