PSI - Issue 64

Abdalla Elhadi Alhashmi et al. / Procedia Structural Integrity 64 (2024) 1990–1996 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1993

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3. Case study: corroded concrete column 3.1. Description

The experimental work conducted by Ma et al. (2022) on corroded confined concrete columns was used to validate the framework of analysis. The test specimens were submerged in an electrochemical solution to simulate uniform corrosion damage on the transverse reinforcements. A 5 mm thick steel frame was added to the top margins of the concrete column to prevent concrete spalling. The columns were subjected to a concentric loading process at a rate of 5 kN/s until the occurrence of corrosion-induced cracks. Subsequently, the loading method was switched into a displacement control, with a rate of 0.5 mm/min, until the specimen reached failure. Deformations were quantified in the central region of the column utilizing linear variable differential transducers (LVDTs) positioned at a distance of 400 mm. Refer to Ma et al. (2022) for detailed information about the experiment.

3.2. Model Development

A non-linear 3D FE model was developed to validate the proposed framework of analysis. Figure 2 illustrates the model configuration, loading and boundary conditions.

R epf roei nntc e

50mm

600mm Roller support ( = 0) Steel frame

50mm

Ro(ller support z = 0)

(a)

c t o h U r e

12 mm in Dia. rebar nr si fi oo rnmo n stirrups

(b)

Roller support ( y = 0)

6mminDia. Stirrups @100 mm

(c)

Fig. 2. FE model configuration: a) corrosion induced cracked column with two visibly cracked faces (Note: crack image is adopted from Ma et al. (2022) ); b) geometry dimensions, loading and support conditions c) steel reinforcement details.

Ten-node quadratic tetrahedron elements were employed for the concrete volume, while the 3D truss elements were used for the reinforcement cage. The embedded region constraint was used to specify the host (concrete) and embedded regions (reinforcement cage) in the model. Concrete damage plasticity (CDPM) was used to model the material nonlinearity of concrete. The analytical models by Mander et al. (1986) and Cornelissen et al. (1986) were used to model the compression and tension behaviors, respectively. The measured values for the compressive and tensile strengths of the concrete were 25 MPa and 2.56 MPa, respectively. The concrete stiffness was measured to be 24.96 GPa. The steel reinforcement cage was assumed to be linearly elastic- perfectly plastic. The longitudinal and transverse reinforcements of the steel had nominal yield strengths of 460.8 MPa and 325.8 MPa, respectively. The cross-sectional area and yield strength of the stirrups were reduced uniformly, assuming a 14% corrosion weight reduction. The corrosion depth is assumed to be equal to the concrete cover. The boundary conditions were implemented at the top