Summary of the main problems
The basic equations of EN 1591

Problem: the definition of gc in EN 1591-2 is not analogous to the definition of the creep coefficient in draft standard Pr EN 13555, which specifies the test procedures for determining the joint coefficients used in EN 1591.

Problem: this coefficient does not appear in the 2001 version of EN 1591. On the other hand, a new coefficient C₁ was introduced in EN 1591-2 of 2001. The latter seems to be involved in taking account of the same phenomenon, but its value is only defined for fiber joints, and its definition is not explicit (page 5 ENV 1591-2 2001: "C₁: numerical constant"). No value of C₁ for a joint of a different type from the fiber joint is given in the standard, and it therefore seems difficult to use this coefficient in practice. Carrying out a parametric study varying C₁...