PSI - Issue 70

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ScienceDirect

Procedia Structural Integrity 70 (2025) 223–230

Structural Integrity and Interactions of Materials in Civil Engineering Structures (SIIMCES-2025) Mechanical and Microstructural Behavior of Foamed Concrete with Polypropylene Fibers and Mineral Admixtures C. Raghu Rami Reddy a,* , H. Sudarsana Rao a , Vaishali. G. Ghorpade a a Department of Civil Engineering, JNTU Anantapur,515002, India Abstract This study investigates the mechanical strength and microstructural properties of foamed concrete, which is made to a density of 1200 kg/m³ and enhanced with 10% mineral admixtures (fly ash, metakaolin, or silica fume) in place of cement and 0.8% polypropylene (PP) fibers by volume. To improve matrix cohesiveness, three improved mixes were compared to a baseline mix of cement, water, foam, superplasticizer, and natural sand. Compressive, flexural, and split tensile strengths were evaluated at 7, 14, 28, 56, and 90 days. Refined pore architecture and uniform fiber dispersion in changed mixtures were revealed by scanning electron microscopy (SEM).The silica fume mix showed the greatest strength gains and microstructural improvements, thanks to its fine particles and strong pozzolanic activity. Combining PP fibers with mineral admixtures improves durability, strength, and crack resistance, making foamed concrete more suitable for structural applications. These advancements offer lightweight, sustainable construction options while minimizing structural dead loads. Ongoing study is recommended to investigate long-term durability and alternate fiber types to improve performance. Keywords: Foamed Concrete; Polypropylene Fibers; Mineral Admixtures; Microstructure; SEM; Silica Fume; Metakaolin; Fly Ash; Natural Sand ; © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of International Conference on Structural Integrity Organizers 1. Introduction A lot of people are interested in using foamed concrete in new building because of its low density, excellent thermal insulation, and sustainability advantages by Amran et al. (2015). With densities typically ranging from 400 to 1600 kg/m³, it offers significant reductions in structural dead load and improved energy efficiency in buildings by Kearsley & Wainwright. (2002). However, its broader adoption in load-bearing applications is hindered by its

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2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of International Conference on Structural Integrity Organizers 10.1016/j.prostr.2025.07.047