PSI - Issue 84

Emeka John Ude et al. / Procedia Structural Integrity 84 (2026) 1294–1301

1299

as increase of the number of fiber layers. A total of 5 improved retrofit approach was realized as outlined in Table 4 . Fig. 8 shows the load curves of all improved strengthening approach.

(a)

(b)

(c)

Fig. 7. Load curve of half-joint strengthened with FRCM (a) RTF-0, (b) fiber RTF-45, (c) RTF 0+45

Table 3. Variation between numerical and experimental campaign

Reference

Experimental peak load (kN)

Numerical Peak load (kN)

Variation

REF

537 568 532

531 566 546 570

-1.1%

RTF-EXP-0 RTF-EXP-45

-0.35% +2.6% -0.35%

RTF-EXP-0+45 572

Fig. 8. Load curve of improved retrofits

Table 4. Results of improved strengthening approach

Reference RTF-IMP-0 RTF-IMP-45 , RTF-IMP-0+45

Description

Experimental retrofit (kN)

Improved retrofit (kN)

Reduced spacing (15 mm) with (1) fiber layer Reduced spacing (15 mm) with (1) fiber layer Reduced spacing (15 mm) with (2) fiber layer

568 (5.77%) 532 (0%) 572 (6.5%)

591 (11.29%) 575 (8.29%) 636 (19.77%) 687 (29.38%) 583 (9.79%)

RTF-IMP-0+45+0 Reduced spacing (15 mm) with (3) fiber layers RTF-IMP-0+45+0’ Original spacing (38 mm) with (3) fiber layers

- -

Values in bracket are the respective improvement to the original beam capacity (numerical model)

It is observed that the RTF-IMP-0+45+0 presented the highest capacity improvement with retrofitted capacity of 687 kN representing a 29.38% improvement of the original beam capacity. Although the RTF-IMP-45 had the lowest improved load, 575 kN (8.29%) this is still much better than the highest strengthening outcome from the original experiment ( Table 4 ).