Selection of soft asphalt pavements for low-volume roads in Lithuania

Abstract

In Lithuania pavement structure of low-volume roads satisfy the 6th class according to normative documents where annual average daily traffic is up to 500 vehicles per day. According to normative documents the thickness of pavement frost resistance structure is reduced. But in winters of 2010/2011 and 2011/2012 a very high freezing index was observed. It led to frost heaving, cracking, loss of bearing capacity and numerous defects in spring. Preliminary investigations showed the need to pay attention to the top 30 cm of subgrade, which has to be constructed with low frost sensitive soils or need treatment. These additional works would significantly increase the road construction costs up to 25 %. As an alternative solution the use of soft asphalt pavements was proposed. This technology is widely used in Nordic countries. But in Lithuania it has never been applied. Research on the designed soft asphalt mixtures was carried. Also, it was proposed the recommendation for soft asphalt pavement structure for low-volume roads in Lithuania.