The effect of water in and between asphalt pavement layers has been noticed and tested since the 1960-s, and the idea that asphalt pavements are not impermeable has been shortly proven.
However, similarly to various countries, road pavements in Hungary are still considered impermeable on the level of national regulations regarding design and certification. Despite a high number of literature in this matter, and the existence of a European Norm and proven methods and equipment to measure permeability of asphalt pavements in the laboratory and in-situ as well, there is typically little or no requirement referring to the testing and required values that indicate the presence and flow of water either in the mix, or the pavement structural design stage, or regarding the requirements for built layers. Although the effect of water can be severe over time, affecting the performance of the layers and the pavement structure.
The paper presents field study showing the effect of water on the state of in-service layers, the standard European method and equipment to test permeability of asphalt layers, and laboratory permeability tests conducted on core samples and laboratory samples. After a high number of permeability tests, void content vas determined for tested specimens. The effect of asphalt mix void content on the permeability are shown, depicting that void contents otherwise acceptable by current standards and also international practice may lead to, in fact, permeable layers.

asphalt permeability, pavement moisture, air void content