Impact resistance of high strength-high ductility concrete

The behavior of thin slabs of High Strength-High Ductility Concrete (HSHDC) under multiple, moderate-velocity impacts is investigated via drop-weight impact experiments. HSHDC is a newly developed fiber-reinforced cementitious composite with unique combination of compressive strength (> 150 MPa) and tensile ductility (> 3%). The deformation mechanisms, cracking patterns, and impact load resistance of HSHDC slabs are determined and contrasted with the behavior of slabs made of a fiber-reinforced Ultra-high Performance Concrete named Cor-Tuf with compressive strength of about 200 MPa. While the HSHDC slabs exhibit ductile flexural behavior with well-distributed multiple fine cracks, the Cor-Tuf slabs exhibit quasi-brittle flexural and shear failures accompanied by large localized cracks and excessive spalling. Finite element analysis of these slabs' responses reveals that the observed difference in the structural behavior of HSHDC and Cor-Tuf slabs is a direct result of the difference in the tensile ductility of these two materials.