SYNTHETIC MACRO-FIBER REINFORCED CONCRETE: MICROSTRUCTURAL CHARACTERIZATION AND MECHANICAL PERFORMANCE

Abstract

Synthetic macro-fiber reinforced concrete has emerged as a viable alternative to conventional reinforcement systems due to its potential to enhance mechanical performance and control cracking behavior. This chapter investigates the microstructural, thermal, and mechanical characteristics of concrete reinforced with synthetic macro-fibers, aiming to establish correlations between material structure and macroscopic performance. Experimental analyses included thermal characterization of the macro-fibers using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), as well as microstructural and mineralogical evaluations of the composite through Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Concrete mixtures with different macro-fiber contents were produced and tested under axial compression at 7 and 28 days. The results indicate that the incorporation of synthetic macro-fibers does not adversely affect compressive strength while contributing to improved post-cracking behavior and enhanced fiber–matrix interaction. Microstructural analyses revealed homogeneous fiber distribution and adequate bonding with the cementitious matrix, supporting the observed mechanical performance. The findings confirm the technical feasibility of synthetic macro-fibers as reinforcement elements in cement-based composites and provide a scientific basis for their application in structural and semi-structural concrete systems.