Strength behavior and microstructural properties of engineered geopolymer composites reinforced with fiber and carbon nanotubes

The main binder in concrete, which is extensively employed in building, Portland cement, is condemned for having a major negative environmental impact. In the field of civil engineering, engineered geopolymer composites (EGC) are a very promising substitute that offers improved sustainability while utilizing comparable special material features to ECC. Environmentally friendly EGC have mechanical properties like traditional Portland cement, however they are susceptible to cracks during tensile and flexural loadings. In this study, polypropylene (PP) fibers and functionalized multi-walled carbon nanotubes (f-MWCNTs) were employed to enhance the ductility of ground granulated blast furnace slag (GGBS)-based EGC (GGBS-EGC). The effect of employing f-MWCNTs and PP fibers was examined by mechanical tests, which comprised single-crack tension assessments, three-point bending, uniaxial tension, and compression tests. The GGBS-based engineering geopolymer showed a peak tensile strength of 3.65 MPa, an elongation of 5.48%, an initial tensile fracture strength of 2.42 MPa, and a compressive strength of 38.03 MPa after 28 days of curing. Having crack widths of 74.56