Drying shrinkage and creep properties of prepacked aggregate concrete reinforced with waste polypropylene fibers

Prepacked aggregate concrete (PAC) is a particular form of concrete that is manufactured by placing and packing aggregates with different sizes in a formwork, and the spaces between the aggregates are then filled through the injection of cement grout with high flowability. This study proposed the prepacked aggregates fiber-reinforced concrete (PAFRC), which is a newly developed concrete, with a unique combination of coarse aggregate and short polypropylene (PP) fiber that is premixed and placed in the formworks. This study presents the outcomes of an investigational work that addresses creep and drying shrinkage performance in addition to the strength development of PAFRC specimens. In addition, palm oil fuel ash (POFA) was used at the substitution level of 20%. Six mixes comprising fiber volume fractions of 0-1.25% with a length of 30 mm were cast by gravity technique. Another six mixtures with the same fiber volume fractions were cast using a pump to inject the grout into the formwork. The experimental outcomes exposed that utilization of waste PP fibers and POFA improved the compressive strength of PAFRC mixes. The drying shrinkage and creep of PAFRC mixes reduced significantly with the addition of waste PP fibers. Moreover, due to the lower drying shrinkage and creep, as well as the unique production technique, PAFRC could be used for several innovative applications in construction.