Typically, strain-hardening cementitious composites (SHCC) utilize high tensile strength (>800 MPa) fibers, such as polyvinyl alcohol (PVA) and ultra-high-molecular-weight polyethylene (UHMW-PE). High tensile strength is necessary to sustain sufficient crack-bridging stress after the first crack and allow subsequent formation of multiple cracks without reducing load transfer capacity. This study presents SHCC development using low tensile strength (<400 MPa) polypropylene fibers. The study utilized two types of in-house developed core-shell bicomponent polypropylene fibers - with smooth and rough outer surfaces (using CaCO₃). The CaCO₃ nanoparticles in the fiber outer shell increased the fiber-matrix frictional bond. Micromechanical modeling guided the SHCC development utilizing low cracking strength magnesium-silicate-hydrate (MSH) cementitious matrix. The study also presents composite optimization using micromechanical theory to achieve tensile strain-hardening for different fiber lengths. The composite material characterization demonstrated compressive strength above 40 MPa and tensile ductility up to 9.7%.