Concrete Crack Dynamics: A Comprehensive Analysis of Cracks on Concrete Beams

This study presents a detailed investigation into the mechanical performance and fracture behaviour of ordinary concrete in comparison with Fibre Reinforced Concrete (FRC) incorporating Polypropylene and Steel fibres. A thorough experimental methodology was employed, encompassing the design and preparation of concrete mixtures, followed by advanced analysis of fracture patterns and microstructural responses using ZEISS imaging software. Key parameters such as crack propagation, strain development, and failure mechanisms were systematically evaluated. The experimental results revealed that Steel Fibre Reinforced Concrete exhibited the most pronounced crack width, measuring 4.87 mm, while Polypropylene Fibre Reinforced Concrete recorded a crack width of 2.64 mm, and ordinary concrete showed the smallest crack width of 1.96 mm. In terms of strain behaviour, Steel FRC achieved the highest maximum strain value of 49.99 %, indicating superior deformation capacity. This was followed by Polypropylene FRC at 21.42%, and ordinary concrete with a significantly lower strain capacity of 7.98%. Statistical analysis confirmed a significant variation in strain capacity between the two types of Fibre-reinforced concrete, particularly emphasising the superior performance of steel Fibres in enhancing ductility and controlling crack expansion. These findings underscore the benefits of Fibre reinforcement—especially with steel Fibres—in improving the structural resilience and durability of concrete, making it a promising approach for advanced civil engineering applications and infrastructure design. Major Findings: The study confirms that Steel Fibre Reinforced Concrete (SFRC) exhibits the highest strain capacity and the widest crack width, indicating superior energy absorption and load-bearing capability. Polypropylene Fibre Reinforced Concrete (PFRC) provides moderate improvement in crack control and strain capacity compared to ordinary concrete, enhancing its toughness. Statistical evidence supports that Fibre reinforcement—especially with steel Fibres—significantly improves crack resistance, strain distribution, and overall structural integrity of concrete.