Full-Scale Test of High Early Strength Bonded Concrete Overlay Design and Construction Methods

Abstract

For rehabilitation of concrete pavements, resurfacing with a bonded concrete overlay (BCO) may provide significantly longer life and reduced maintenance costs. Two important issues are bonding and rapid reopening of resurfaced sections. The project objectives were to determine a method of constructing a BCO under extreme weather conditions in El Paso, Texas, that would ensure early opening to traffic and achieve design requirements for long-term performance, and to investigate methods of detecting and mapping delaminations nondestructively. A BCO test slab that was designed and constructed for a full-scale test of feasible design and construction alternatives is reported. The month of June was selected for the test because severe environmental conditions were expected. The experimental variables encompassed in eight test sections were reinforcement of concrete (plain, polypropylene fiber–reinforced, and steel fiber–reinforced), use of shear connectors (nails and anchors), reinforcement, surface preparation, and day or night construction. A weather station was used to record air temperature, relative humidity, and wind speed. By combining these data with concrete temperatures, evaporation rates could be calculated. Several nondestructive testing methods were used to attempt to detect and map delaminations. The results developed from the test are presented in terms of observations during construction, weather and slab temperatures, coring and pull-off testing, delamination detection, cracking, and slab loading. Recommendations are made for construction and quality control of BCOs for early opening to traffic.