The Influence of Climate on Libyan Roads Deterioration

Abstract

The Libyan climate, which is characterized by hot arid climatic region (high variation in daily temperatures, high solar radiation, low humidity, low rainfall intensity, wind and dust storms), lies between 15° and 45° both north and south. Asphalt pavement roads are the main and only source of the Libyan overland transportation system for most passengers and goods. Most of Libyan deteriorated roads are passing through a hot arid climatic region (Libyan Desert); Libyan roads expected design life is 20 years, but these roads do not last so long due to aging rapid deterioration and cut down of service life. The tendency for the asphalt binder to harden and age under atmospheric influences has been known and studied for many years. Therefore, high solar radiation in the hot arid climate region in Libya with presence of oxygen accelerates and increases the physical, chemical, and photochemical processes in the asphalt binder. While the pavement in midday of summer season can be heated by the solar radiation to more than 70 °C, it may be cooled down in some extreme cases to freezing temperatures during the night. This swinging and fluctuation of solar radiation and temperatures induces thermal stresses and causes fast aging in the asphalt pavement layers. Therefore, the deterioration in the form of thermal cracking became a problem in cold regions as well as in hot, arid climate regions with great variation in daily temperatures. The aim of this paper was to estimate the solar radiation energy and present the influences of Libyan climate conditions on road deterioration.