R J Thomas, Andrew J Fellows; Andrew D Sorensen
Dept. of Civil and Environmental Engineering, Utah State Univ.
Admixtures; Coarse aggregates; Durability tests; Freeze thaw durability; High strength concrete; Permeability; Reclaimed asphalt pavements; Recycled materials; Thermal expansion
The strength reduction associated with the replacement of the virgin coarse aggregate in concrete with recycled asphalt pavement (RAP) limits the use of the RAP concrete to nonstructural applications. Recent research has suggested that RAP concrete might retain sufficient strength for structural applications if high-strength concrete mixture designs were used. Before these high-strength RAP concrete mixtures can be used in transportation infrastructure applications, their durability must be proven. This study evaluated the chloride permeability, the freeze-thaw durability, and the coefficient of thermal expansion of high-strength RAP concrete mixtures. The results indicated that the chloride permeability of the high-strength concrete, as measured by the surface resistivity, was unaffected by the replacement of up to 50% of virgin coarse aggregate with RAP. Furthermore, the freeze-thaw durability of high-strength RAP concrete was improved over high-strength concrete with 100% virgin coarse aggregate. The optimal RAP fraction in terms of the freeze/thaw durability was 35% by mass. Finally, the coefficient of thermal expansion was minimally affected by the replacement of up to 50% of virgin coarse aggregate with RAP. On the basis of these results, the durability of high-strength concrete with RAP coarse aggregate was deemed sufficient for transportation infrastructure applications.