This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, I(gal), and the corrosion currents, I(corr), estimated from the polarization resistance, R(p). Sensors have...

This paper presents a non-destructive test method for steel corrosion in reinforced concrete bridges by using a 3-dimensional digital micro-magnetic sensor to detect and analyze the self-magnetic field leakage from corroded reinforced concrete. The setup of the magnetic scanning device and the measurement mode of the micro-magnetic sensor are introduced. The numerical analysis model is also bui...

This paper presents an in-situ inspection and experimental investigation on the pore solution pH of concrete cover for the corrosion initiation of rebars under a long-term natural carbonation reaction. A 77-year-old steel mill was inspected, and 35 concrete column cover samples were collected to test the pH of the pore solution and phase compositions layer by layer. The variation in pH and phas...

The bond between concrete and reinforcement bars is very important to develop the composite behaviour of reinforced concrete. Bond strength is influenced by several factors such as bar diameter, cover of concrete over the bar, spacing of bars, transverse reinforcement, grade and confinement of concrete around the bars, aggregates used in concrete, type of bars and coating applied on bars, if an...

The inhibition effect of Vernonia amygdalina (bitter leaf) extract on the corrosion behaviour of embedded mild steel rebar in concrete has been investigated by electrochemical potential measurement, pH and gravimetric (weight loss) methods. The results were further analysed using the two-factor ANOVA test. The experiments were performed using bitter leaf extract as a green inhibitor in 3.5% sod...

Linear Polarisation Resistance (LPR) can provide a direct evaluation of the instantaneous rate of corrosion. However it has the disadvantage of requiring a localised breakout of the concrete cover to provide an electrical connection to the steel reinforcement. This paper describes an adaptation of the LPR method and the four-point Wenner resistivity method to give an evaluation of the rate of s...

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. Project Title: Long-Term Performance of GFRP Reinforcement URL: http://tti.tamu.edu/documents/0-6069-1.pdf 16. Abstract Significant research has been performed on glass fiber-reinforced polymer (GFRP) concrete reinforcement. This research has shown that GF...

Mechanically stabilized earth walls, MSEW, around Florida were instrumented through their concrete covers to survey corrosion rates of galvanized strip soil reinforcement by polarization measurements. The first broad survey was made 10 years ago as a baseline and a new survey is currently underway to assess long term corrosion rate trends. Initial results of an ongoing survey confirm low rates ...

Durability of reinforced concrete (RC) structures is affected by certain environmental conditions and operational actions which can reduce their lifetime significantly. Among these actions, this paper proposes a stochastic model that accounts for the combined effects of chloride-induced corrosion, climate change and cyclic loading. Separately, corrosion leads to cross-section reduction, climate...

Chloride induced corrosion in concrete is a well-known issue. Although numerous researchers have attempted to quantify the chloride threshold limits (CT) in different concrete systems (with little consensus), the issue of allowable admixed chlorides (CA) in concrete is still very much unresolved. For example, The CA limits specified by the American Concrete Institute (ACI) committees range from...