Correcting concrete slab movement or pumping problems by subsealing is common practice. Subsealing fills voids beneath the slab, eliminating pumping and restoring uniform support to the slab, hence prolonging slab life. The north carolina department of transportation has experienced accelerated slab cracking after subsealing operations in several projects. The problem has caused enough concern that a study was initiated to investigate the procedure of subsealing operation and the performance of slabs that were stabilized by subsealing. In order to compare reliability of different void detection techniques, several devices were used to locate voids beneath concrete slabs in a test road. Test results indicated that none of these devicesproduced compatible data. The test section was monitored for 4 years. Conditions of stabilized and unstabilized slabs were mapped and analyzed. Results indicated that, if not handled properly, subsealingcan cause performance problems. This paper appears in transportation research record no. 1307, Pavement analysis, design, rehabilitation, and environmental factors 1991.
Abstract