PSI - Issue 78

Pasquale Bencivenga et al. / Procedia Structural Integrity 78 (2026) 1545–1552

1549

Table 3 – Concrete compressive and steel tensile strengths Code n

Rck [MPa] σ c,adm [MPa] fyk [MPa] σ s,adm [MPa]

12 16 25 30 40 50 15 20 25 30 40 50 15 20 25 30 40 50

4.00 5.00 7.78 8.33 9.44 6.00 7.25 8.50 9.75 10.56 12.25 14.75

8

R.D. n.2229 of 16/11/1939

310

200

10

160 220 240 260

320 380 410 440

M.D. 30/05/1972

10

6.00 7.25 8.50 9.75

160 220 260

320 380 440

M.D. 26/03/1980

15

12.25 14.75

The analyses firstly provided the calculation of the bending resisting moment of each r.c. cross section according to the indications of the current Italian technical code (NTC2018) through the ultimate limit state methodology, using the partial safety factors of both materials. Subsequently, these values were compared with those evaluated according to each historical standard previously described (1939, 1972 and 1980) based on the calculation with allowable stresses. 4. Results and discussion The parametric study focused on evaluating the past-to-current code ratio in the bending capacity assessment based solely on the variation of the considered technical standard. Figure 1 shows the results of the analyses in terms of ratios between bending moment capacities defined according to the different design codes.

(a)

(b)