Discussion on Papers 14 and 15

Dr Richmond (Paper 15)

The levels of stress at particular points of a finite element solution are not in themselves of significance, but the guidance given by the finite element results when considered in conjunction with the structural mechanisms involved is a valuable design tool. The magnitude of the changes in the stress and internal force systems due to creep-temperature interaction are of an order which invalidates the use in that manner of any finite element solution of a concrete structure which does not allow for this phenomenon.

2. In Paper 15 (Fig. 6) concrete stresses were shown for a thermal gradient of 5 to 50°C across a wall. Fig. 1 shows the corresponding stresses in the reinforcing steel. The effect of thermal strains and the load from axial prestress are shown separately but the same temperature distribution is assumed in both for calculating rates of creep.