Field and Laboratory Performance of Cementitious Partial Depth Repair Materials in Cold Climates

Abstract

Incompressible debris accumulating in pavement joints or cracks restricts the free expansion of pavement slabs during warm weather and generates excessive compressive stresses along the joint or crack faces. These stresses cause deterioration and spalling of slab corners and edges and accelerate the rate of pavement degradation. Partial depth repair is a preventative maintenance treatment which is commonly used early in the pavement service life to repair spalls and shallow deterioration and restore the intact pavement surface typically before excessive deterioration occurs. The selected repair material must be compatible with the environmental and load conditions. Replacing the deteriorated concrete with a durable material restores the structure integrity, improves the ride quality, and reduces moisture infiltration to subsurface layers of the pavement. The objective of this paper is to evaluate the performance of several rapid setting cementitious concrete repair materials in cold climates and to develop selection criteria for partial depth repair materials. Six repair materials were applied to a test section on a major arterial road in the City of Winnipeg in the summer of 2010. Pre- and post installation detailed condition surveys were conducted at the repair sites and the field evaluation will continue for the next two years. The field performance of the repair materials was evaluated according to: presence of transverse and longitudinal cracks, separation between the material and concrete slab, surface finish of the repair area, and deterioration of the repair material. Laboratory tests were conducted to evaluate the impact of freeze-thaw and wet-dry cycling on the bond strength between repair materials and regular concrete. Concrete cylinders were prepared in the laboratory. The prepared cylinders had a concrete-repair material interface slanted at 30 degrees from the loading axis. The specimens were subjected to freeze-thaw and wet-dry cycling separately. The degradation of the bond strength between repair material and concrete was evaluated from the compressive testing of the bond cylinders at different levels of freeze-thaw and wet-dry conditioning. Results of laboratory and field evaluation will be used to develop performance-based selection criteria for cementitious partial depth repair materials.