Effect of the future increases of precipitation on the long-term performance of roads

Abstract

The long-term performance of the road network of the province of Quebec
(Canada) is strongly influenced by climatic conditions (Dore and Zubeck, 2008). Amongst other
factors, high levels of saturation in soils and pavement materials are an important cause of
pavement deterioration. According to climate change scenarios established by Ouranos (2012),
the South of Quebec will undergo a monthly precipitation increase between -0.1% and 8.45% for
a future horizon from 2010 to 2039. The purpose of this project is to quantify the effect of these
expected precipitation increases on the mechanical behavior of road structures, materials and
soils. Based on data collected on instrumented road sections, a relationship between
precipitations increase and saturation level of pavement layers is proposed. In order to determine
the existing relationship between mechanical properties and moisture content, the resilient
modulus and permanent deformation behaviors for various moisture contents and four different
subgrade soils were determined using triaxial tests, the later being validated using a small-scale
heavy vehicle simulator. Using the precipitation increase scenario and the relationship developed
between precipitation and pavement layers moisture content in Quebec, a damage analysis is
performed to quantify the decrease of pavements service life caused by climate change. It is
found that climate change, and more precisely the increase of precipitations expected in the
Province of Quebec, will have a significant impact on pavement performance and that adapted
pavement structures and materials, such as improved drainage, increased structural capacity or
materials with reduced sensitivity to water, are possible options to reduce the loss of pavement
service life associated with climate change.