DEVELOPMENT OF A CYCLIC WATER VAPOUR TEST FOR DURABILITY ASSESSMENT OF BITUMINOUS MIXTURES FOR PAVEMENT MATERIAL

Studies on the durability assessment have generally been performed to gain an information on the resistance of bituminous mixtures against water. This paper proposes a new equipment to investigate the influence of water vapor on durability. The proposed method involves subjecting samples to cycles on evaporation - condensation at 60 o C. Evaluation of the proposed method was based on the Marshall Index of Retained Stability and durability index value. The results show that index of retained stability after vaporization test follows a pattern of durability similar to that of the immersion test. However, the difference of index of retained strength between maximum and minimum values is more significant for the water vaporization - condensation test than that for the immersion test. This is an indication that the proposed procedure is sufficiently severe and the apparatus of the cyclic water vapor test can be used for durability assessment of bituminous mixtures.