A polymer-modified hybrid-fibers cementitious composition has a one-day compressive strength of at least approximately 17 MPa, a 28-day tensile strength of at least approximately 3.8 MPa, an ultimate tensile strain of approximately 3% to approximately 9%, and a 7-day bond strength of at least approximately 2.3 MPa. A binder of ordinary Portland cement, fly ash, and silica fume is provided. Other components include limestone powder, sand, superplasticizer, and water. The composition further includes one or more of styrene butadiene rubber or ethylene-vinyl acetate copolymer in an amount ranging between approximately 2% and approximately 8% by mass of binder. Fiber additives include steel fibers in an amount ranging between approximately 0.3% and approximately 3.0% by volume of the cementitious composition and polymer fibers in an amount less than approximately 1.0% by volume of the cementitious composition. Chamfers made of the composition are positioned at beam-column joints.