Testing of an Ultrahigh-performance Concrete Overlay Developed Using Local Materials

The superior mechanical and durability properties of ultrahigh-performance concrete (UHPC) offer significant potential advantages when used as an overlay material—a common method for extending the service life of concrete bridge decks. Providing high compressive strength, improved environmental resistance, and increased service-life expectancy compared to conventional concretes, UHPC mixture proportions can be adapted using local materials. Flexural testing of a high-performance concrete (HPC; 66 MPa) prestressed channel beam bridge girder was conducted to investigate the use of nonproprietary UHPC (120 MPa) developed using materials primarily local to New Mexico, USA, for bridge deck overlays. The girder was first subjected to cyclic loading (minimum 1000 load-unload cycles to deflection-based service load conditions) to establish baseline performance and behavior. The girder surface was then textured, and a 25 mm nonproprietary UHPC overlay was cast. Cyclic loading was repeated for the girder-overlay system before loading the system to failure to investigate post-cracking flexural behavior. The UHPC overlay developed satisfactory bond with the HPC substrate without a bonding agent and exhibited no visible signs of distress or debonding after cyclic loading. Comparative analyses indicated increased stiffness and capacity for the girder- overlay system.