多相复合导电沥青混凝土的制备
目录
目录 (1)
摘要
沥青混凝土广泛应用于高等级公路和机场跑道。沥青混合料的电阻率约为107-109Ω*m,属于绝缘体材料。通过掺入适量的导电相材料，改善沥青混合料的电学性能，可望获得多功能的沥青混凝土，将会对沥青路面冬季融雪化冰、路
面损坏检测等产生深远的影响。
导电沥青混凝土的级配设计采用Superpave设计方法，合成曲线尽可能远
离禁区，提供足够的矿料间隙率来填充高掺量的导电相材料。导电粉末可作为
一部分填料，但与矿粉的密度差异大，需折算成当量矿粉质量。通过掺入石墨
和碳纤维可改善沥青混凝土的导电性能。石墨的润滑性和吸油性及碳纤维的分
散性分别限制其在导电沥青混凝土的应用。石墨单位体积对沥青混凝土导电性
能改善效果良好，与其它导电相材料复合时,改善作用显著，可作为导电沥青混凝土的主要导电相材料，少量碳纤维作为辅助导电相，同时碳纤维代替部分矿
粉既可起增强作用。掺入少量短切碳纤维可明显改善导电粉末填充沥青混凝土
的导电性能，发挥碳纤维大的长径比所具有的导电桥梁作用和导电通路短接作用，改善电子的导电机制。
石墨对沥青的吸收能力强，评价导电沥青混凝土的体积性能指标必须考虑吸收沥青。马歇尔残留稳定度试验、冻融劈裂试验和车辙试验表明石墨导电沥青混凝土的抗水损害能力强，高温稳定性能良好，可作为新型路面使用。通过控制沥青用量和石墨用量，增加沥青混凝土的压实度，可获得稳定的导电性能。
关键词:沥青混凝土；导电；材料组成；路用性能
Abstract
Asphalt concrete has been extensively applied in expressway and runway of airfield. It belongs electrical insulating material with a resistivitvy of 107-109Ω*m. The conductive behavior of asphalt mixture can be improved with the addition of conductive materials,thus a multifunctional Asphalt concrete can be obtained，which would have a profound effect on pavement deicing, damage testing and so on.
Superpave design method was employed to design the mix Proportion of electrically conductive asphalt concrete. The curve of mix Proportion kept away from the restricted zone in order to provide enough voids in mineral aggregate to fill the high content of conductive materials. Conductive Powder can regard as a part of filler in asphalt concrete. But they need to make a conversion for equal quality of limestone powder because of the deference of the density. The conductive behavior of asphalt mixture can be improved by adding graphite and carbon fiber. The absorbing oil nature and lubricated effect of graphite and the bad dispersion of carbon fiber limit their application in ECAC respectively. The improving effete of graphite on the resistivity of ECAC is excellent，and the composite modification with other
conductive materials also is obvious. Graphite was used as main component，and a few carbon fibers were added as assistant component. carbon fibers replaced a part of limestone powder，which has an enforcement effete on asphalt concrete. The conductive performance of conductive Powder filling asphalt concrete is improved by adding a few chopped carbon fibers. Carbon fibers Play a role of the conductive bridge effect and the short circuit effect because of high long/diameter ratio，improving the conductive mechanism of electron.
Graphite absorbs asphalt in liquid state strongly. The evaluation of volume performance of ECAC must take absorbed asphalt into account. Experimental results of Marshall Remnant Stability Test，Water Susceptibility Tensile Strength Ratio Test and Rutting Test show that graphite modified ECAC possesses of high anti-water damage ability and excellent high-temperature stability，which is expected to apply as new-type pavement. Stable conductive performance can be achieved by controlled graphite content and asphalt content and increasing the compact degree.
Key words: Asphalt concrete;Electrical conduction;Material component;conductive mechanism;Pavement performa
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