Application and Evaluation of Micro-Cracking on Cement-Stabilized Bases at Field Projects in Louisiana

Abstract

Cement stabilized soil bases have been used in flexible pavements in Louisiana for years. Soil cement has an excellent load carrying capacity and durability, but is also well-known for developing shrinkage cracks, which can reflect through asphalt concrete surfaces and accelerate the deterioration of asphalt pavements. Micro-cracking is a special reflective cracking mitigation technique used in cement-stabilized base construction. The objectives of the research were to determine the effectiveness and performance of micro-cracking on soil-cement pavements. Micro-cracking was applied on field projects, based on the experience of a previous micro-cracking research project at the Pavement Research Facility of the Louisiana Department of Transportation and Development. Two pavement sites were selected for the field pavement rehabilitation projects, LA 1003 and LA 599, to test the micro-cracking technique. In-situ tests were conducted and pavement performance was monitored for both sites. It was found that an 8.5-in. micro-cracked soil cement pavement showed a similar or better early performance as compared to a non-micro-cracked soil cement pavement with regards to the overall cracking performance. On the other hand, more cracks were found on the micro-cracked test sections than the control sections when micro-cracking was applied on a 12-in. cement treated soil base in Louisiana. Analysis of the structural numbers did not show a significant difference between the control and micro-cracked sections. Further monitoring is recommended for both of the field projects.