Overview and first steps of experimental research using recovery filler to replace limestones mineral filler in hot mix asphalt

Abstract

The world's research experience has shown that it is possible to use recovery filler to replace limestone mineral filler, and that there are different types of recovery filler derived from different basement rock that can be effective use for hot mix asphalt. Some preliminary experimental studies on the use of recovery filler to replace BK in laboratory conditions have also been carried out. Recovery filler used has the same origin as the coarse and fine aggregates in the asphalt mixture, which is a magmatic rock with basic characteristics, with the chemical composition of two main oxides, SiO2 43.17% and CaO 13.46%. When using recovery filler, initially there were positive signals, the parameters of hardness and softening temperature all tended to increase when increasing the content of recovery filler. The air voids Va of the hot mix asphalt achieved better values at 25% and 100% of the recovery filler content, the minimum value of Va corresponds to the rate of 25% of the recovery filler. Combined with the index of the penetration and the softening temperature, it can be temporarily seen that the use of BĐTH 25% is giving relatively positive signals about the usability for the asphalt mixture.