Water susceptibility of asphalt mixtures: Testing the effect of adhesion agents on different binder/aggregate mixtures

Abstract

One of the objectives of the Norwegian PROKAS project 1998-2004 was better durability of asphalt pavements. In a laboratory study of water susceptibility of asphalt mixtures, tests were conducted on asphalt mixtures containing three common aggregates and bitumen 160/220. The aim of the study was to: a) compare three different test methods b) study the effects of different additives (liquid amine, hydrated lime, limestone and
combinations of these). The test methods were:

1) The “Cantabro test” after water conditioning of the asphalt specimen as described in prEN 12697-12.
2) “The Rolling bottle test” on the aggregate fraction 5.6/8.0 mm.
3) The Swedish "Shaking abrasion test", a modified version of the prEN 12274-7.

Hot mixed asphalt specimens with maximum aggregate size 2 mm were tested after water conditioning. The three test methods showed reasonably good agreement on the tested materials, even though they may be considered as complementary methods. The tests results showed that the use of adhesion agent should be recommended for certain aggregate/bitumen mixtures. For one of the binder/aggregate combinations none of the used adhesion agents were effective. All of the three test methods are recommended for durability testing for production control and for research and development.