Study on preparation method of strength and morphology controlled aggregates used in asphalt mixture

Abstract

In the past two decades, it has been possible to analyze the effect of aggregates morphology on the mechanical properties of asphalt mixture by numerical simulation. Because of the randomness and uncontrollability of natural coarse aggregates morphology properties, the validation of numerical simulation and research on basic performance and characteristics of asphalt mixtures were still challengeable. In this paper, using fly ash, bauxite residues and bauxite as raw materials, feldspar, MnO2, talcum-AlF3 as sintering additives, artificial aggregates(AAs) were pelletized for batch production with 3D printing mold. After sintering process, AAs with specific morphology and high strength were prepared. RSD algorithm was applied to explore the interactions among sintering additives and determine the optimal content of materials. The results revealed that AAs achieved lower weared stone value, bulk specific gravity and open porosity compared with diabase. The crushed stone value, polished stone value, solmdness, and adhesiveness of AAs were comparable to diabase. Compared with granite, AAs with a small percentage of bauxite residues exhibited comparable mechanical performance and chemical properties but higher open porosity and water absorption.