Opening and out‐of‐plane shear fracture performance of steel and natural sisal hybrid fiber reinforced concrete

• Published in: Structural concrete : journal of the FIB 2024-04
• Main Authors: Sreekumaran, Sreenath, Krishna, Arathi, Karuppanan, Kathiresan
• Format: Article
• Language: English
• ISSN: 1464-4177; 1751-7648
• DOI: 10.1002/suco.202301081

The key objective in developing sustainable concrete is enhancing performance by mitigating adverse environmental effects simultaneously. Using short and discrete steel fibers to reinforce the concrete matrices is a widely accepted approach to improve the ductility of concrete. Although the utilization of traditional steel fibers enhances the strength of the concrete, it simultaneously leads to an increase in its weight. Also, the production of steel fibers is an energy‐intensive and carbon‐emitting process. To attain sustainability, it is imperative to reduce the use of steel fibers by including a suitable alternative through the hybridization of fiber reinforcements. The concrete developed in this study was composed of a ternary blended binder containing Ordinary Portland Cement, Ground Granulated Blast furnace Slag and Microsilica. Fibers were hybridized by partially replacing 25%, 50%, and 75% of steel fibers with natural sisal fibers. Mixes reinforced with 100% steel fibers and 100% sisal fibers were also assessed for better understanding. Basic properties such as workability, compressive strength, and splitting tensile strength were assessed. Fracture performance of the prepared mixes under pure and mixed, opening, and tearing modes of loading was also assessed by conducting disc bending tests. It can be observed from the results that, steel fibers can be replaced with sisal fibers up to 25% of the total fiber volume without greatly compromising the workability, strength and fracture performance of concrete. Hence, hybridizing steel fibers with sisal fibers can be considered a viable option to reduce the overall weight of the structural components, which can further help reduce the environmental impacts and overall cost of concrete production.