Effect of Subbase Type and Subsurface Drainage on Behavior of CRC Pavements

摘要

As part of an extensive study conducted to determine the significant relationship between the behavior of CRC pavement and various design features, an evaluation was made of four types of subbase and three types of subsurface drainage systems. Deformation of the subbase due to loading and/or subbase erosion under severe climate and moisture conditions can cause severe pavement distress. To prevent or delay these types of pavement distress from developing early in the service life of the pavement, some type of stable subbase and subsurface drainage system is necessary. The pavement behavior, expressed in terms of transverse cracking and deflections, was analyzed and correlated with the type of subbase and type of subsurface drainage system. The investigation also includes the procedure used to evaluate the efficiency of the drainage systems and to expand the knowledge of the stress levels in the steel. The pavement sections containing the various subbases and subsurface drainage systems are performing excellently after 6 1/2 years of service. The lime-stabilized soil mixture as subbase offers the potential for reduced construction costs, and it is recommended that additional sections be built for further evaluation. The subsurface drainage system with longitudinal underdrains placed at the edge of the stabilized subbase was the most efficient in removing free water from beneath the pavement structure and has been adopted by Illinois as the standard treatment for interstate highways.