Evaluation of the Use of Magnesium Chloride for Surface Stabilization and Dust Control on Unpaved Roads

Abstract

Gravel roads are an important portion of the road network in western Argentina, and their maintenance requires a huge amount of economic and human resources. Recently, the use of alternative treatments based on the application of mineral salts such as hydrous magnesium chloride, also known as bischofite, has been introduced in this region. Such treatments are being applied for dust control and surface stabilization on unpaved roads. This paper presents the main results obtained during a research project carried out by the National University of San Juan, Argentina, along with local road agencies and companies. Test sections of gravel roads were treated with bischofite applied in two ways. Over 18 months, measurements of surface roughness and dust emission were made on those sections. The main results show that the use of bischofite contributed to a notable reduction in the evolution of roughness and dust emission as compared with untreated gravel sections. Bischofite appears to be appropriate not only for the environment but also for road agencies and road users; important cost savings were verified through economic assessments that compared treated and untreated gravel road sections.