Innovation of parameter αcc for design resistance of high-strength concrete columns

Abstract

Original scientific paper The usage of high-strength concrete has been increased significantly in recent decades. By increasing the compressive strength of concrete, stress-strain features of concrete are changed. In contemporary technical regulations specific provisions for high-strength concrete are proposed. EN 1992-1-1 comprises concretes to the class C90/105. According to EN 1992-1-1 reduction factor for value of concrete compressive strength for design αcc, depends on two parameters, none of which compressive strength of concrete. Test results have shown that calculation of bearing capacity of columns, with recommended αcc and curved-rectangular stress block is non-conservative for high-strength concrete. It was shown that coefficient αcc should be redefined by introducing of new parameter which will cover differences of less design strength for high strength concrete. In many countries value of 0,85 is used for αcc, as proposed in their National Documents. Correlation between calculated capacity of columns and experimental results was used for its redefining.