PSI - Issue 64

Noëmie Delaplanque et al. / Procedia Structural Integrity 64 (2024) 1492–1499 Noémie DELAPLANQUE/ Structural Integrity Procedia 00 (2019) 000 – 000

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Table 1. Key properties of the GFRP reinforcement supplied by the manufacturer. Rebars Nominal diameter (mm) Effective area (mm²)

Guaranteed tensile strength (MPa)

Modulus of elasticity in tension (GPa)

GFRP

10

71

900

46

(a)

(b) Fig. 1. Photo (a) and microscopic observation (b) of the GFRP rebar studied.

The selected concrete was a high-strength formulation based on a CEM III cement, as outlined in Table 2. The gravel used was sourced from the quarry of Gray (Haute-Saône, France). Following fabrication, the samples were immersed in water for 2 months and then dried in air for 1 month. The extended immersion period of 2 months was chosen to accommodate the slow hydration rate characteristic of CEM III. Table 2. Composition of the high-strength concrete Component Quantity (kg/m 3 ) Cement (CEM III-A) 375 Sand 0/4 810 Gravels 4/14 1130 Water 150 Superplasticizer (0.88 %) 3.3 2.2. Sample description The interface properties were characterized using the pull-out test method as recommended by ACI 440.3R-12 (2012) and AFGC (2023). Cylindrical samples were selected following the approach of Rolland et al. (2015). However, to reduce the global volume of the test specimens, we used smaller cylinders of diameter 110 mm. To ensure representative results favouring pull-out failure modes over concrete splitting, internal steel reinforcement was incorporated and a bonded length of 4 times the FRP rebar diameter was adopted due to the high concrete strength. It should be noted that this bonded length is slightly shorter than the traditionally adopted value of 5 or 6 times the FRP rebar diameter.

Fig. 2. Scheme of the tested pull-out samples geometry and steel reinforcement details.