Fresh and Hardened Properties of Concrete with Fractionated Reclaimed Asphalt Pavement

A study was completed to investigate the changes in fresh and hardened properties when using coarse, fractionated reclaimed asphalt pavement (FRAP) as a partial replacement of virgin coarse aggregate in a ternary blended concrete. The FRAP replacement levels were 0, 20, 35, and 50%. The ternary blended concrete consisted of 65% Type I Portland cement, 25% Grade 100 ground granulated blast furnace slag, and 10% Class C fly ash. Two coarse FRAP sources were investigated: one washed (16 mm maximum size) and one dirty (12.5 mm maximum size). The dirty FRAP source was additionally processed in the laboratory by washing and sieving over a 4.75 mm sieve to reduce the amount of fines and agglomerated sand/asphalt particles. The fresh concrete properties showed that adding FRAP had little to no effect on the air content, increased the slump, and reduced the unit weight. The fresh and hardened concrete characteristics (compressive, split tensile, and flexural strength) demonstrated that replacement levels up to 35% FRAP could be utilized without compromising existing concrete material specifications for paving. Surprisingly, washing the coarse dirty FRAP did not provide any strength benefit over the dirty, unprocessed FRAP for the sources evaluated.