Experimental Investigation on Deterioration Mechanisms of Concrete under Tensile Stress-Chloride Ion-Carbon Dioxide Multiple Corrosion Environment

Jun Shen,Xiangsheng Chen

doi:10.3390/jmse10010080

Abstract

The adverse effects of a hostile marine environment on concrete structures inevitably result in great economic loss and may contribute to catastrophic failure. There is limited information on the durability of concrete in a tensile stress-chloride ion-carbon dioxide (TCC) multiple-corrosion environment. The objective of this study is to explore the impact of a TCC multiple-corrosion environment on concrete considering three coupled factors of compressive strength, Cl− penetration, and carbonation. Dry–wet cycle tests were conducted to determine the strength degradation and Cl− penetration concentration of concrete in a hostile multiple-corrosion marine environment. The results show that the effects of water-soluble chloride ions (Cl−), carbon dioxide (CO2), and tensile stress on concrete are not a simple superposition, but involve obvious interaction. The compressive strength of a concrete specimen first increases and then decreases in chlorine salt-carbon tests. The Cl− concentration and tensile stress affect the carbonation depth of concrete, which increases with an increase in Cl− concentration, and with the application of tensile stress. The Cl− concentration has an obvious effect on the carbonation depth. In addition to experimental observations, a stepwise regression equation was established based on the multiple linear regression theory. A correlation analysis considering different factors was conducted to reflect the corrosion results more directly.

Highlights

It is known that concrete structures undergo chemical corrosion and stress in a marine environment [1]
Subsequent theoretical models have been based on this formula to consider factors affecting carbonation, and allow the modification of the carbonation coefficient, such as the carbonation model proposed by Papadakis et al [6], which is more applicable to the calculation of carbonation depth in ordinary Portland cement concrete
The purpose of this study was to investigate the durability of reinforced concrete structures in a tensile stress-chloride ion-carbon dioxide (TCC) multiple-corrosion environment

Summary

Introduction

It is known that concrete structures undergo chemical corrosion and stress in a marine environment [1]. Concrete carbonation durability analysis models can be categorized in three types: empirical models, theoretical models, and multi-field coupled numerical models [4]. Empirical models are based mainly on experimental data from a certain structure type to determine the relationship between water/cement (W/C) ratio, CO2 concentration, strength, other parameters, and carbonation depth. Multi-field coupled numerical models can fully reflect the influence of different factors on carbonation, but the calculation process involves many complex partial differential equations and is inconvenient to apply. Subsequent theoretical models have been based on this formula to consider factors affecting carbonation, and allow the modification of the carbonation coefficient, such as the carbonation model proposed by Papadakis et al [6], which is more applicable to the calculation of carbonation depth in ordinary Portland cement concrete. Wang et al [8] proposed multiple-coefficient carbonation models based on the

Objectives

Results

Conclusion