Modeling the Shape of Compaction Curve for Asphalt Stabilized Soil

Abstract

The knowledge and modeling of the exact shape of the laboratory compaction curve provides a means for a good understanding of the susceptibility of soil to water. The models provide effective means for quantifying the sensitivity of the compaction process to the various factors affecting the process. The basic mathematical description of soil compaction is the relationship between molding moisture and the dry density. Two types of soil and three types of cutback asphalt have been implemented in this investigation to understand the influence of cutback asphalt addition on the sensitivity of compaction curve shape in terms of the changes in slope for dry and wet sides of optimum condition, and to verify if such changes follows a significant sequence. It was concluded that pure and asphalt stabilized SC-Soil compaction curve exhibits a flat trend at both dry and wet sides of optimum moisture content, therefore, a straight line was implemented. While pure and asphalt stabilized CL-Soil exhibits bell shape trend at both dry and wet sides of optimum moisture content. A straight line was implemented for modeling the dry side of optimum, and a parabolic curve was implemented for wet side of pure soil and for soil with 4% cutback asphalt. When 3% of MC-0 cutback asphalt was introduced to SC-Soil, the maximum dry unit weight was increased by 23.5%, meanwhile, the optimum fluid content was reduced by 21%. When 4% of MC-30 cutback asphalt was introduced to CL-Soil, the maximum dry unit weight was decreased by 5.5%, and the optimum fluid content was increased by 6.5%.