Development of an evaluation protocol to estimate the long-term performance of secondary materials in road construction

Résumé

Future performance of secondary materials in road construction is often difficult to
estimate. In this study, aging is proposed as a means of exploring the long-term mechanical
and physical performance of secondary materials. Blast Furnace Slag (BFS) material,
routinely used in the Netherlands as a cementitious material was selected as a reference
material in this aging approach. A motorway in the Netherlands (the A32 motorway) was
used as a source of field aged BFS materials. The base layer of this motorway, suddenly
experienced serious failures. Three types of aging treatments were chosen and applied to the
cylinders made with the fresh materials and A32 field aged materials. These aging treatments
are being normal aging, steam aging and freezing-thawing cycles. The aging methods affected
the mechanical and chemical performance of material. Response variables measured in the
laboratory and in the field were mostly similar and the acquired results from the laboratory
aging methods suggesting that the aging methods produced a material of similar distress.
Steam aging produced loss of strength which indicated that steam aging can contribute to the
occurrence of deleterious reactions. Microscopic techniques were used to analyze this
reaction. The study of response variables showed there is a linkage between compressive
strength, expansion, micro cracking and amount and type of binder.