Influence of Adding Different Amounts of Super Plasticizers and Macro Polypropylene Fiber on the Mechanical Properties and Microstructure of Roller Compacted Concrete

Laboratory experiments were conducted to assess the influence of incorporating varying quantities of superplasticizers and Macro PP Fiber on the mechanical properties and microstructure of roller-compacted concrete. The investigation comprised nine concrete mixtures, including a baseline mixture (C1) representing conventional concrete without superplasticizers and fiber. Additionally, five mixtures (C2, C3, C4, C5, and C6) incorporated different concentrations of superplasticizers (0.7%, 1.0%, 1.5%, 2.0%, and 2.5% of the cement content). In comparison, the remaining three mixtures (C7, C8, and C9) included varying amounts of Macro PP fiber (1, 3, and 5 kg/m ³ of concrete, respectively). The findings reveal a direct correlation between the superplasticizer content and both compressive and tensile strengths Additionally, the results indicate that the inclusion of polypropylene fibers in roller-compacted concrete yielded satisfactory mechanical strength outcomes. The PP fibers were strategically positioned about the cracks, enhancing the overall durability and resilience of the concrete.