PSI - Issue 81

Roman Rybak et al. / Procedia Structural Integrity 81 (2026) 255–259

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Process of recording pipe deformations

P-1

Digital indicators

P-2

Analog-to-digital converter

P-3

Fig. 2. Data acquisition system scheme for investigating the deformed state of the strengthened reinforced concrete pipe.

3. Results Continuous experimental tests were conducted to assess the deformations of the reinforced concrete pipe strengthened using the sleeving method with a reinforcing cage. The evaluation criteria for the pipe’s deformed state were the onset of surface cracking in the specimens and the moment of complete failure. The test results are presented in Table 1.

Table 1. Test results of the reinforced concrete pipe strengthened using the sleeving method with a reinforcing cage.

Pipe deformation measurement points P-1 P-2 P-3 Deformations, mm

Data at the time:

Formation of cracks on the pipe

5.73 6.72

1.02 1.79

5.13 6.11

Pipe destruction

Table 1 shows that the largest deformations of the reinforced concrete pipe strengthened with an added reinforcing cage occur in the vertical direction. The maximum vertical deformation at the crown at the onset of cracking was 5.73 mm, on the lateral horizontal side – 1.02 mm, and at the base – 5.13 mm. During specimen failure, the maximum vertical deformation at the base reached 6.11 mm, at the crown – 6.72 mm, and on the lateral horizontal side – 1.79 mm. Figure 3 presents the graph of deformation magnitudes as a function of applied load for the tested specimen, where P-1, P-2, and P-3 correspond to the digital indicators according to their placement scheme (Fig. 2). The onset of cracking occurred at a load of 7.15 kN. The ultimate failure load for the strengthened reinforced concrete pipe was 16.85 kN.

Fig. 3. Graph of deformations as a function of applied load.

Diagrams of the deformation distribution of the reinforced concrete pipe strengthened using the sleeving method at the onset of cracking (Fig. 4a) and at the moment of complete failure (Fig. 4b) are presented in Fig. 4.