Study On The Filler In Asphalt Concrete

The role of the filler in asphalt paving mixtures is quite important when it is combined with asphalt, though the proportion is small. Presently, the significance of it has not been recognized adequately in our country. The control parameters for characters of the fillers in technical specification are too broad, and the key indices that have main effects on the asphalt mortar and mixture are not clear. The comprehensive study on the impact and mechanism of mineral fillers, as fly-ash, Portland cement, slag-powder, hydrated lime and so on, improved asphalt concrete stability is scarce.To solve above-mentioned problem, this paper mainly researches on the fillers such as lime stone fines, fly ash, Portland cement, slag-powder and hydrated lime. Firstly, the physico-chemical characters of them are comprehensive analyzed, and the characteristic of them are summarized. Secondly, the performance in high and low temperature and fatigue of asphalt mortar is studied by using the Superpave equipments such as DSR and BBR. The performance of asphalt mortar composed with different sorts of fillers are estimated and the factors that having prominent influence are analyzed. Thirdly, the performance of asphalt paving mixture composed with different sorts of fillers is researched, and the improve effects of different sorts of fillers are gained. The key indices affecting the asphalt paving mixture are analyzed. Fourthly, the filler-asphalt interface is studied according the surface chemical theory. The adhesion-stripping mechanism is discussed with the performance of fillers, asphalt mortar and paving mixture. Finally this paper put forward the key index of filler that influent the pavement performance of asphalt paving mixture, and give advices about index of filler to the Technical Specification.