Application of aging methods to evaluate the long-term performance of road bases containing blast furnace slag materials

Abstract

The long-term performance of secondary materials is becoming a challenging aspect in road construction since their future behaviour is difficult to estimate. In this study, aging is proposed as a means of exploring the long-term mechanical and physical performance of secondary materials. A Blast Furnace Slag (BFS) mixture which is routinely used in the Netherlands in road base construction, e.g. in the A32 motorway, was selected as a reference material. Twenty years after its construction, the A32 pavement structure experienced serious failure and the BFS base contributed to that. Accordingly, an aging protocol was suggested to detect at an early stage potential poor material performance. Two types of accelerated aging approaches were applied to the materials being steam aging and cyclic freezing and thawing. The results show that there is a linkage between the material performance and temperature, moisture, chemical composition and time. The response behaviour, of aged laboratory samples and the field-aged A32 base material, suggested that the aging methods did a reasonable job in detecting materials with a poor performance.