Mix Design for Pavement Overlays for Sustainable Development
Mix Design For Pavement Overlays For Sustainable Development Contributing nearly 5% of global anthropogenic greenhouse emissions through cement production alone, the concrete industry is a major contributor to global climate change. Automobiles and trucks that use concrete transport infrastructure release another 30% of anthropogenic greenhouse emissions. The construction, repair and rehabilitation of concrete pavements, together with these atmospheric emissions, rely on the production and flow of large quantities of concrete material and its constituents.
Fundamental micromechanics carefully guide this green material design to maintain under tension the pseudo-strain hardening material behavior. This ductile behavior, more than 500 times greater than conventional concrete, is critical to the second mechanism for sustainability enhancement. ECC ductility suppresses reflective cracking, a major cause of premature overlay failure, thereby increasing durability and reducing life-cycle maintenance.
By incorporating industrial waste, more than 70 percent of ECC virgin components have been replaced without reducing critical mechanical performance characteristics. Compared to conventional concrete overlays, significant sustainability improvements were modeled when coupled with a possible 50 percent reduction in overlay thickness and extension of service life.
Engineered cement composites (ECC) exhibit many of the desirable features for high-performance pavement applications, including excellent durability, high ductility, and cracking resistance. The ECC material tests show improved performance in shrinkage cracking behavior, fatigue and substrate bond testing, freezing thaw exposure, abrasion and wear testing, long-term material performance, and accelerated weather testing compared to plain concrete testing.
Furthermore, the use of ECC materials in demonstration projects with the Michigan Department of Transportation, including bridge deck patching and a link slab project, reveals that ECC is a viable high-performance material choice for various transport applications. The use of greener cement materials for the rehabilitation of rigid pavement systems represents a great potential for the reduction of material and energy resource consumption and pollutant emissions.