Mechanical properties and energy absorption capacity of plain and fiber-reinforced single- and multi-layer cellular concrete

Abstract

Cellular concrete has been widely used in geotechnical, non-structural, and structural applications because of its low density and easiness of handling. Due to its high energy absorption capacity, the material is also viable for applicants, such as the engineering material arrested system (EMAS) and emergency escape ramp (EER). However, commonly used single-layer or uniform cellular concrete often does not exhibit desirable structural functionality and efficiency under loading, as the material tends not capable of withstanding load after peak load is reached. Multi-layer cellular concrete (MLCC) could possess the solution by withstanding increasing loads at different layers as the MLCC failed or compressed layer by layer. Moreover, fibers can strengthen and improve cellular concrete's structural integrity by bridging the initial cracks. This paper evaluates the compression, push-in penetration, impact resistance, and flexural performance of plain and fiber-reinforced single-layer cellular concrete and MLCC. Results show that MLCC can maintain structural integrity under compression even after completely fracturing the weaker layers. Similarly, results from push-in (penetration) resistance tests also exhibit multiple peak loads when the penetrator reaches different layers, indicating the potential to respond effectively to varying levels of stress. For impact resistance, MLCC exhibits higher absorption capacity and better structural integrity with fewer cracks observed. While plain MLCC showed similar peak acceleration to the lower-density cellular concrete (400 kg/m3) used in this study, fiber-reinforced MLCC exhibited approximately 27% lower peak acceleration compared to the lower-density fiber-reinforced cellular concrete. The study also demonstrated significant structural integrity improvement in cellular concrete when fibers are incorporated, with peak loads and maximum displacements improved by approximately 82%, and 470%, respectively, when MLCC is placed under flexure load.