Performance Characteristics of Concrete Paver Blocks Incorporating Individual and Combined Fractions of Reclaimed Asphalt Pavement Aggregates under Different Curing Regimes
Sumit Nandi, G.D. Ransinchung
Abstract
The present study investigated the performance characteristics of concrete paver block (CPB) mixes with incorporated reclaimed asphalt pavement (RAP) aggregates under different curing regimes, namely, continuous water curing (WC), air curing (AC1 and AC2), intermittent water and air curing (WAC), water spray curing (WSC) and heat curing (HC). Seven CPB mixes were formulated by volumetrically replacing virgin coarse and fine aggregates partially and in combination with coarse RAP, fine RAP, and combined RAP fractions. For better refinement of agglomerated particles present in the RAP and to achieve a dense microstructure, the block specimens were fabricated using a design methodology that included a staged mixing approach and time-controlled compaction simultaneously with a vibratory hammer and table vibrator. Hardened CPB specimens were tested to assess mechanical (compressive, flexural, and tensile splitting strength) and durability (water absorption, porosity, and carbonation) properties of the concrete. CPBs fabricated from the considered RAP-inclusive concrete mixes manifested great potential to be used for pavement applications having medium to very heavy traffic when cured with the WC, WAC, WSC, and AC2 curing regimes. Curing regimes WAC and WSC, which involved a combination of water and air curing, were found to be the most effective for the RAP CPB mixes, resulting in superior strength properties. The presence of carbonation was detected in all the RAP CPB mixes when exposed to air curing (AC2) for a prolonged period of time.