A study on the influence of water and fines on the deformation properties of unbound aggregates

Abstract

To achieve proper stability in base coarse materials, there is a variety of parameters to optimize. The response of the material is a combination of several factors, such as grading, water content, material strength, stress level etc. It is well known that the grading of a material is important for the stability and that a well graded material normally gives better stability than a
single sized or a less graded material. In the Norwegian guidelines for pavement design there are restrictions to ensure that the fines content is under a certain level to ensure a none-water susceptible material and hence avoid loss of bearing capacity during spring thaw. In this study the main focus is to study how the deformation properties, elastic as well as
permanent deformation behavior, are affected by different combinations of water content, grading and material strength. The grading of the material is based on the gradation curves for base course material in the Norwegian guidelines for pavement design, which is based on the fuller curve. Cyclic triaxial tests have been used to study the material behaviour in the laboratory.