Influence of Various Adhesion Promoters on Asphalt Behavior by Assessment of Water Sensitivity

Resumé

Bitumen to aggregate adhesion represents one of the fundamental
characteristics of asphalt mixes which are closely connected to their durability and resistance
to water and frost effects. With respect to increased focus on construction cost effectiveness it
is preferred to use locally available aggregate sources. These are often hydrophilic and not
suitable enough to secure sufficient adhesion. Another factor is the quality of bitumen used
for asphalt mixture production which bears with respect to advanced distillation processes and
general business preferences of petrochemical industry another risk affecting the adhesion.
Based on these assumptions different chemical adhesion promoters have been used and
compared. At the same time mechanically activated microfillers based on lime and/or flyashes
have been used as mineral adhesion promoters or intelligent substitutes to traditional
filler. Asphalt mixes of ACbin16 or ACwear11 type have been laboratory designed with two
different types of aggregates. Indirect tensile strength has been assessed for all mixes
according to EN 12697-23 with determination of water sensitivity according to EN 12697-12
and by modified test procedure described by AASHTO T-283 used in the U.S..