The Response of Pumice Lightweight Concrete to Low Velocity Impact Loading

Each year, engineers face significant sustainability challenges due to the large-scale production of concrete for buildings and infrastructure. To address this issue, alternative materials are being used. In this study, volcanic pumice, a lightweight material, was used to replace traditional coarse aggregate. Additionally, Glass Fibers (GFs) and Fiberglass Mesh (FGM) were incorporated to enhance the concrete's performance. The research experimentally examined the ability of lightweight concrete to absorb shocks, using volcanic pumice as the coarse material. The impact resistance was assessed by applying frequency impacts on a concrete plate caused by a falling weight, a 3.4 kg iron ball with a diameter of 9.5 cm, dropped from a height of 1.5 m. The number of strikes at the first fracture as well as the number of blows needed to cause failure, was recorded. An average of three specimens measuring 50 cm × 50 cm × 5 cm were tested at the ages of 28, 60, and 90 days. The study evaluated five pumice lightweight mixes: a reference mix without fiber, a 1% GF mix, a 1-layer FGM mix, a 3-layer FGM mix, and a hybrid mix (M hybrid) incorporating both GF and a 3-layer FGM. The results showed that the hybrid mix performed best in resisting repeated impact loads and absorbing energy. The performance improved by 350% compared to the reference mixture at 90 days. Identifying the impact resistance of lightweight aggregate concrete made with sustainable pumice aggregate could open new opportunities for using this type of concrete in structures exposed to low-velocity impact loads.