Towards development of a risk management tool for roads affected by dryland salinity

Abstract

There is a popular assumption that damage to roads due to high soil salinity is one of the greatest economic effects of dryland salinity. There is little scientific evidence to back up these claims. The effect of salt on road materials is not documented or understood. This study started as an attempt to develop a risk management tool for roads in saline areas using geophysical techniques. EM38 and EM31 surveys were carried out effectively and safely on major and minor rural roads. They relate to changes in salt content in the road basecourse and underlying subgrade. The lack of scientific understanding of the effects of salt on road material has resulted in a focus on understanding how the road is affected. Mineralogical and geochemical changes are indicated that may result in volumetric and strength changes to the road pavement but more work is needed.