An Improved Micromechanical Framework for Saturated Concrete Repaired by the Electrochemical Deposition Method considering the Imperfect Bonding

Qing Chen,J Woody Ju,Zhengwu Jiang,Yaqiong Wang,Zhiguo Yan,Hehua Zhu

doi:10.1155/2016/1894027

Abstract

The interfaces between the deposition products and concrete are not always well bonded when the electrochemical deposition method (EDM) is adopted to repair the deteriorated concrete. To theoretically illustrate the deposition healing process by micromechanics for saturated concrete considering the imperfect interfaces, an improved micromechanical framework with interfacial transition zone (ITZ) is proposed based on our recent studies. In this extension, the imperfect bonding is characterized by the ITZ, whose effects are calculated by modifying the generalized self-consistent model. Meanwhile, new multilevel homogenization schemes are employed to predict the effective properties of repaired concrete considering the ITZ effects. Moreover, modification procedures are presented to reach the properties of repaired concrete with ITZs in the dry state. To demonstrate the feasibility of the proposed micromechanical model, predictions obtained via the proposed micromechanical model are compared with those of the existing models and the experimental data, including results from extreme states during the EDM healing process. Finally, the influences of ITZ and deposition product on the healing effectiveness of EDM are discussed based on the proposed micromechanical model.

Highlights

Over the past 20 years, many meaningful studies have been published on the electrochemical deposition method (EDM), which is a promising repairing approach for concrete in aqueous environment and has been applied to marine structures and other situations in which traditional repairing methods are limited [1,2,3,4]
Based on our recent works [15, 18], this paper presents an improved micromechanical framework to describe the healing process of saturated concrete considering the imperfect bonding between the deposition products and the concrete matrix
Let CS, C4, and CT represent the stiffness tensor of the equivalent particle, the intrinsic concrete, and the equivalent composite of the saturated concrete repaired by EDM with interfacial transition zone (ITZ)

Summary

Introduction

Over the past 20 years, many meaningful studies have been published on the electrochemical deposition method (EDM), which is a promising repairing approach for concrete in aqueous environment and has been applied to marine structures and other situations in which traditional repairing methods are limited [1,2,3,4]. Based on our recent works [15, 18], this paper presents an improved micromechanical framework to describe the healing process of saturated concrete considering the imperfect bonding between the deposition products and the concrete matrix. Deposition products and water are considered as different inclusion phases in the saturated concrete In this extension, the interfacial transition zone (ITZ) is considered with the interphase model to characterize the imperfect bonding phenomenon between the deposition product and the intrinsic concrete [8,9,10, 12, 13]. See details for our previous work [15]. φFw is the volume fraction of the water phase in the two-phase composite composed of the water and the deposition products, Vwat denotes the volume of the water, and Vdep signifies the volume of the deposition products

The Second-Level Homogenization for the Equivalent

Verification and Discussion

Results in this study Upper bounds

Conclusions