Glass fiber reinforced concrete: overview of mechanical and microstructural analysis

This study compares the mechanical properties and microstructural characteristics between a control concrete and a reinforced concrete by incorporating various doses of glass fibers. Glass fibers (GF) were used in different volumetric proportions 0.5%, 1%, 1.5% and 2%, randomly placed in the mix. The fiber dimension was 51.3 mm in length and 0.05 mm in diameter. Cylindrical and prismatic specimens were prepared for testing at 7, 14 and 28 days for a water/cement ratio of 0.687; no superplasticizer was used in any experimental mix. Mechanical strength tests were carried out for both the control concrete and for each percentage of glass fiber, in order to determine the optimum dosage of addition and to perform a detailed analysis of the microstructure. Experimental studies reveal remarkable improvements in compressive strength, elastic modulus, flexural strength and tensile strength over the control concrete values, with increases of up to 40.29%, 18.50%, 37.28% and 38.30%, respectively, at 28 days of curing. However, it is observed that exceeding the optimum percentage of 1.5% GF causes a decrease in strength no less than that of the control. In the sample with the optimum percentage, the XRD test revealed elevated values of silicate, calcium and silicon oxide. The results of the concrete enriched with fiberglass stand out for generating a significant impact on its mechanical and microstructural properties. This material can not only be used in non-structural elements but also in structural elements for a sustainable construction industry.