Impact resistance of oil palm shells concrete reinforced with polypropylene fibre

This study examines the results from an investigation on the impact resistance of oil palm shells (OPS) concrete. The use of OPS as a substitute for regular aggregate in lightweight concrete will help reduce its negative environmental influence. There is a lack of research on the impact resistance and crack behaviour of concrete; specifically in OPS lightweight concrete reinforced by polypropylene (PP) fibre. The replication of a low-velocity projectile effect on slab samples was achieved by dropping two types of steel ball (weighing 0.380 kg and 1.25 kg), with drop height of 360 mm, through the utilization of a self-fabricated drop-weight impact test rig. A total of 12 cube specimens, with dimensions 100 x 100 x 100 mm, were used to prepare 36 slabs with various thicknesses. The 36 slabs were prepared using a concrete cutting machine to excise the three cube specimens from each mixture, into 20, 30 and 40 mm thicknesses. Impact resistance tests were then performed on them. The results demonstrate that there was a strong linear relation between volume fraction of PP fibre and impact resistance; as well as crack resistance ratio. This relation was indefeasible by changing the thickness from 20 mm to 30 mm and 40 mm. Although increasing the thickness improved the impact resistance significantly, the effect was more pronounced for ultimate failure crack resistance than for first crack resistance. (C) 2016 Elsevier Ltd. All rights reserved.