Structural Properties of High Strength Concrete and its Implications for Precast Prestressed Concrete

The authors have presented a useful overview of the properties of high strength concrete that are of concern to structural engineers and the design profession. They state in their conclusions that the material level, high strength concrete is less ductile than normal strength concrete, but at the sectional level for reinforced concrete elements, if the ratio p/ pb is kept constant, the deflection ductility is essentially independent of the strength of concrete. • This conclusion is perhaps a little optimistic and needs some further clarification and caution. An extensive parametric evaluation was conducted by the discussor 3tl using a computerized nonlinear analysis and the same stress-strain curves for concrete (of compressive strength between 5 to 13 ksi) as those used by the authors. Sectional duc-