PSI - Issue 70

R. Mohanraj et al. / Procedia Structural Integrity 70 (2025) 409–416

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1. Introduction Concrete is the most widely used construction material globally because of its versatility, strength, and durability. However, the production of conventional concrete involves significant environmental impacts, including the depletion of natural aggregates and high carbon dioxide emissions associated with cement manufacturing (Jiang et al. 2024). The search for sustainable and eco-friendly alternatives has led to the exploration of waste materials such as rubber fine aggregate (RFA) and steel slag (SS) as partial replacements for natural aggregates (Ru et al. 2023). These materials not only help reduce the environmental burden but also contribute to the efficient disposal of industrial and post consumer waste Li and Tier (2024). The durability of concrete, defined as its ability to withstand adverse environmental conditions without significant deterioration, is a critical factor in the longevity and safety of structures (Ho and Huynh 2024). Acid attack and salt encrustation are two common forms of chemical deterioration that concrete structures often encounter, particularly in industrial and coastal environments (Dharmar and John 2023). Acid attack can lead to the dissolution of cementitious materials, weakening the concrete matrix, whereas salt encrustation can cause expansive forces within the concrete, leading to cracking and spalling (Kumar et al. 2024). The corrosion of sewage concrete pipes is a significant issue. Dezhampanah et al. (2020) assessed the durability of concrete with various steel fibres and recycled crumb rubber contents. The findings show that 10% CR and 0.25% SF enhance durability and load capacity, whereas 10% CR and 1% SF improve impact resistance, with reduced CO 2 emissions from CR use (Goudar et al. 2019). Elsayed et al. (2022) investigated the structural behavior of crumb rubber concrete (CRC) short columns under different conditions. CRC columns with varying crumb rubber contents (0%, 10%, and 20%) were tested in laboratory, chloride, and sulfate environments (Eissa et al. 2024). The results show that increased CR content and exposure time degrade the column strength, stiffness, and toughness, especially under sulfate conditions (Bellum et al. 2024). Mhaya et al. (2021) developed rubberized concrete using ground blast furnace slag and discarded rubber tire crumbs (DRTCs). Analytical techniques and an optimized ANN-GA model were used to evaluate the mechanical properties of the samples (Samson et al. 2024; Shanmugasundaram et al. 2022). The results showed that DRTCs (5 – 30%) increased compressive strength, impact resistance, and ductility, making them suitable for practical applications. Substituting rubber particles for coarse aggregates in concrete enhances dynamic properties such as energy dissipation, ductility, and strain-rate sensitivity, despite weakening static properties (El Marzak et al. 2023). Rubber concrete (RC) with a rubber content of less than 30% has improved mechanical and environmental performance, demonstrating good fire resistance, permeability, and freeze-thaw behavior. Abendeh & Bani Baker's (2022) study explored the production of durable self-compacting concrete (SCC) via recycled steel slag aggregates (SSAs). The incorporation of SSA improves mechanical strength and durability, particularly at higher SSA increments, especially when coarse natural aggregate is partially replaced by coarse SSA (Eren and Çevik 2024) . Niş et al. (2023) investigated the impact resistance and mechanical properties of crumb rubber self-compacting alkali-activated concrete with 1% steel fibres (Ravikumar et al. 2024; Ravikumar et al. 2023). The fine and coarse crumb rubber was partially replaced at 10% and 15%, respectively (Bachir et al. 2018). While crumb rubber reduces the mechanical properties, steel fibres compensate, enhancing the impact performance significantly, especially at 15% crumb rubber replacement (He et al. 2023). With the increase in automobile usage, waste tire disposal has become a significant environmental concern. The incorporation of waste tire rubber into concrete as a fine aggregate replacement can enhance economic efficiency and sustainability, as reported by Hasan et al (2024). While crumb rubber reduces workability and density, treated rubber particles and additional binders can improve mechanical properties and durability. The incorporation of waste materials into concrete addresses environmental concerns. Rezaeicherati et al. (2023) evaluated the mechanical properties of recycled concrete with various recycled fine aggregate (RFA) and nanosilica contents. The results revealed improved mechanical performance with nanosilica contents of up to 4.5% (Reddy and Hemadri 2023). The environmental impacts were analysed via the CML 2000 and IMPACT2002+ methods, highlighting sustainable construction practices (Akhtar et al. 2022; Mohanraj et al. 2023). Recycling waste tire rubber in concrete enhances sustainability and durability. According to Li et al. (2019), rubberised concrete (RC) offers enhanced resistance to alkali-silica reactions, sulphate attack, chloride penetration, acid, and freeze-thaw cycles, particularly when it contains 5 – 20% rubber. Fine aggregate replacement and pretreatment of rubber or supplementary cementitious materials optimize RC performance. Valente et al. (2022) compared rubberized geopolymer and Portland