In-situ deformation modulus of rust in concrete under different levels of confinement and rates of corrosion

Abstract

The large uncertainty of the value of the deformation modulus of rust in the literature and the granular property of rust make it difficult to correctly simulate the interaction between the corroded reinforcement and concrete, including rust expansion and bond slip behavior. To fill the gap, this study thereby quantifies the deformation modulus of rust in concrete under different levels of confinement, and takes into consideration the effect of the corrosion rate through an in-situ testing method. To obtain a more accurate deformation modulus of rust, the chemical composition and quantity of rust are examined by using X-ray diffraction. Moreover, the effect of diffusion of rust into concrete porous zone and crack was incorporated into the compressive deformation of rust. The results show new empirical relationships between the deformation modulus of rust and the confinement pressure together with the corrosion rate are obtained. These relationships are further validated by the test results in the literature. The present work can contribute to narrow the uncertainties in the deformation modulus of rust for simulating and predicting the deterioration of concrete structures due to reinforcement corrosion.