Aggregates are a major part of highway construction and its quality as well as strength affects the overall performance of the pavement structure. The base material near the construction site does not always meet the strength requirement needed for the pavement construction and the hauling of quality aggregate increases the construction costs. For better use of local available materials, stabilizing agents such as lime and asphalt cement have been utilized to increase the strength of crushed aggregate bases. Performance of pavement structures is heavily influenced by the thickness of the structure as well as material properties of each layer. The stiffness of the base layer influences the tensile strain experienced by the asphalt layer and the compressive strain in the subgrade layer. The tensile strain at the bottom of the asphalt layer and the compressive strain in the top zone of the subgrade layer are the main components affecting fatigue cracking and rutting resistance of any pavement structure, respectively.
In this study, field performance (rutting, cracking, and surface roughness) of pavement sections with treated and untreated bases were compared to determine the effects of the stabilizing agents of aggregate bases. In terms of fatigue cracking, surface rutting, and pavement surface roughness, the treated sections performed significantly better as compared to the untreated sections. The combined average values of all the three distresses showed a better performance for the treated sections with the fatigue cracking averaging 2.5 times lower than the untreated sections. The combined rutting and roughness (IRI) of the treated sections averaged about 0.08-inch lower and 1.4 times lower than that of the untreated sections, respectively.
Date of publication
Dr. Gokhan Saygili, Dr. Michael Gangone
Gc, Hemant and Souliman, Mena I., "TREATED VERSUS UNTREATED AGGREGATE BASES FOR FLEXIBLE PAVEMENTS: A NATIONWIDE COMPARITIVE STUDY" (2018). Civil Engineering Theses. Paper 11.