Initial moisture and mixing effects on higher quality recycled coarse aggregate concrete

• RCA performs best in concrete when in a partially-saturated moisture condition.
• Two-stage mixing could improve the concrete strength properties.
• Shrinkage of concrete with RCA was not affected by the mixing method.

Higher quality recycled concrete aggregates (RCA) were used as coarse aggregates in a concrete mixture. The initial aggregate moisture condition (oven dry, partially saturated, fully saturated) and mixing method (normal, two-stage) were assessed in order to limit the differences between concrete containing RCA and virgin aggregates. Concrete with partially-saturated RCA using two-stage mixing was beneficial for improving the compressive and split tensile strengths. For this material, the mixing method did not affect the concrete free drying shrinkage at any age. Overall, the two-stage mixing method increased the concrete workability and could potentially improve the concrete strength properties, particularly when the RCA is partially saturated.