Plastic damage analysis of concrete around misaligned dowel bar in jointed concrete pavement

ABSTRACT

Dowel bar misalignment causes stress concentration in jointed concrete pavements, and misaligned dowel bars may lose their ability to transfer loads. To examine this problem, a concrete damage plasticity (CDP) model and a method were implemented using ABAQUS to evaluate its parameters. The CDP model simulated the stress–strain relationship for tension and compression in concrete specimens, and was validated through experimental testing. A three-dimensional finite element model of a misaligned dowel in a jointed concrete pavement was developed, and the equivalent stress, plastic strain, and plastic damage under loads for various misalignment conditions were determined. The simulation results of uniaxial tension and compression in a concrete sample were compatible with the experimental results, demonstrating the high accuracy of the CDP model. Under the action of a wheel load, the concrete below a misaligned dowel undergoes plastic damage. The damage extended from the bottom of the dowel to the sides as the misaligned dowel deviated vertically from the alignment with the pavement’s longitudinal axis, especially in the case of twin bars misaligned in opposite directions. The plastic damage ratio is close to unity, which indicates complete failure of the concrete below the misaligned dowel. The equivalent stress below the dowel tends to be zero and shifts to the sides of the dowel. Consequently, the concrete below the misaligned dowel failed to support the load, reducing the load-carrying capacity of the dowel. When a fully elastic model was used, the stresses below the dowel exceeded the ultimate strength of the concrete, which contradicts the actual occurence. Therefore, the CDP model is recommended for analyzing the stress in the concrete around a misaligned dowel.

KEYWORDS:

• Concrete damaged plasticity model
• plastic damage factor
• misalignment dowel bar
• stresses
• ABAQUS

Acknowledgement

This work was supported by the National Natural Science Foundation of China (Grant No. 51878575.

Disclosure statement

No potential conflict of interest was reported by the author(s).