PSI - Issue 70

R. Ashwathi et al. / Procedia Structural Integrity 70 (2025) 183–190

184

1. Introduction The need for modern construction and infrastructure necessitates a steady supply of concrete and other construction materials because of its adaptability and versatility (Ravikumar et al., 2024). From towering a skyscraper to laying a pavement, concrete demonstrates robust strength durability in retaining structural integrity (Brandt, 2008). To enhance various properties of concrete, different admixtures are incorporated into the mix alongside the cement and aggregates (Najm et al., 2022). One of the significant advantages is its ability to mould into any shapes and resist against high compressive load (Velumani et al., 2023). However, the need to withstand tensile strength under tensile and flexural stress needs an attention (Zhang Guan Yu; Tan, Kang Hai, 2021), (Cao Mehran, 2020). The inherent disparity of concrete between tension and compression has created a critical need for improvising the tensile properties of concrete (Wang Feifei; Lai, Jinxing; Xie, Yongli, 2021). To address the limitation, fibres are included into the matrix. When the fibres are incorporated into the mix, it enhances the strength, toughness and cracking resistance (Khan Mingli; Chaopeng, Xie; Ali, Majid, 2021). These fibres act as a micro reinforcing materials in bridging the cracks and distributing the stress across the structure (Ravikumar et al., 2024). Fibres are small discrete materials that are oriented randomly and distributed evenly across the mix (Khan Mingli; Xie, Chaopeng; Ali, Majid, 2021). Among various fibres, steel fibre and polyester fibre are incorporated in the experimental investigation for its distinctive properties (Frazão B.; Barros, Joaquim A. O.; Bogas, J. Alexandre; Toptan, Fatih, 2019). These materials arrest the crack propagation and control the failure mechanism under different loading patterns (Ravikumar et al., 2023). Steel fibres imparts mechanical and structural properties due to its greater strength and toughness (Fan Weina; Teng, Le; Khayat, Kamal H., 2019). Also, the steel fibres provide superior resistance against thermal stress enabling it to withstand under high temperature and thermal shocks . Polyester fibres are synthetic fibres that have excellent property in mitigating the shrinkage related issues alongside promoting the structural toughness (Haripriya and Ganesh Naidu, 2023). These fibres reduces the plastic shrinkage cracks effectively by reducing the settlement (Farooqi Majid, 2018; Zollo, 1997). They are chemically inert and enhances the resistance against aggressive chemicals (Khan et al., 2022). The fibres when incorporated in hybrid applications, it promotes dual benefits thereby enhancing the integrity of the structural performance under varying loading and environmental conditions (Shanmugasundaram et al., 2022). This innovation is caused due to the demand for growing high performance concrete and sustainable infrastructure (Ravikumar et al., 2023). The durability and degradation contribute towards extended service life of the structure (Cheung et al., 2018). Therefore, it is obvious that in addition to the advantages in the performance, it also offers economic and environmental benefits over the traditional mix (Tošić Stanislav; de la Fuente, Albert, 2020). The research aims at developing a fibre reinforced concrete individually and in a hybrid combination. The ultimate objective is to determine the optimum percentage of fibres to be incorporated into the matrix in improving strength parameters. The following are the acronyms used.

Nomenclature CC

Conventional Concrete

FRC Fibre Reinforced Concrete SFRC Steel Fibre Reinforced Concrete PFRC Polyester Fibre Reinforced Concrete HFRC Hybrid Fibre Reinforced Concrete

2. Materials used The mix follows the guidelines provided by IS: 10262-2009. The proportions are adopted for M30 grade concrete with corresponding water-cement ratio which is crucial in proving a balance between hydration and durability. Fibers were incorporated at 0.25, 0.5 and 0.75 percentages based on the literature study.