Structures In Marine Environment Research Articles

Review of Cathodic Protection Technology for Steel Rebars in Concrete Structures in Marine Environments

This study compared the advantages and disadvantages of various corrosion protection methods for steel rebars and clarified the advantages of the cathodic protection (CP) method in the application of corrosion protection in marine structures. The advantages and disadvantages of sacrificial anodes and impressed current technology for the CP of steel rebars in marine structures were further discussed in detail, and the feasibility of CP applications in practical engineering was evaluated.

A data-based and physics-informed Bayesian updating method for deterioration models of RC structures in marine environment

Deterioration models of reinforced concrete (RC) in marine environment, to be applied to existing structures, usually need to be calibrated with long-term in-situ data. The Bayesian model updating provides a framework to incorporate measured data into existing models to make them more realistic. The measured chloride concentrations of concrete at different depths are related to each other through the Fick’s second law, but they are treated as independent in existing updating methods, which affects the accuracy of model updating. To solve this issue, this paper proposes a data-based and physics-informed (DBPI) likelihood function to incorporate the physical law behind the measured data into Bayesian updating framework, whose validity is first confirmed through numerical examples, and then it is applied to the durability assessment of an existing wharf structure in marine environment. The parameters involved in the chloride ingress model and the critical chloride concentration model are updated using the data from durability inspections. The durability performance of the structure is then assessed using the updated models, which is consistent with the actual surface deterioration observed in the two inspections. Discussion of the updated results reveals that ignoring the physical law behind the measured data may result in incorrect inferences of the chloride ingress model and multi-mode distribution of the updated parameters, which is solved by using the proposed DBPI likelihood function, and the accuracy of Bayesian updating is significantly improved.

Mechanical performance study of PVA fiber-reinforced seawater and sea sand cement-based composite materials

Due to the swift progress in the construction sector, there is a global concern about the potential scarcity of river sand and freshwater resources. The development of new construction materials is considered an inevitable trend for industry growth. PVA fibers, known for their strong corrosion resistance, cost-effectiveness, and high toughness, have the potential to enhance the corrosion resistance and seismic performance of structures in marine environments. However, their mechanical properties and durability in the seawater and sea sand environment are not well understood. Therefore, the investigation of the impact of seawater and sea sand on the mechanical properties and durability of PVA fiber-reinforced cement composites is considered crucial. A mechanical performance analysis of PVA fiber-reinforced seawater and sea sand fiber cement composites was conducted in this study. PVA fiber volume fractions of 0%, 0.75%, and 1.5%, cement composite matrix strength grades of C30 and C50, and curing periods of 28 days, 90 days, and 180 days were examined, investigating their influence on the bending toughness of PVA fiber-reinforced seawater and sea sand cement composites. Specific conclusions include the addition of fibers increased the peak bending load, had a less corrosive effect in seawater, and improved the flexural toughness of the material. The most significant improvement was observed at 1.5% fiber content, where the load-deflection curve was fuller and the energy absorption capacity of the material increased by 33–109%, maintaining good bending toughness. Furthermore, higher fiber contents are required for high-strength cementitious composites to improve flexural toughness and durability. The formulation of calculation formulas for predicting bending strength and corresponding deflection, which fit well with the experimental results; and the development of a calculation model for the bending toughness index of PVA fiber-reinforced seawater and sea sand cement composites, providing an effective prediction of material bending toughness.

Exploring anti-corrosion properties and rheological behaviour of tannic acid and epoxidized soybean oil-based fully bio-based epoxy thermoset resins

This research explores the physicochemical attributes of a fully bio-epoxy thermoset aimed at serving as an anti-corrosion coating for safeguarding carbon steel structures in marine environments. Throughout this investigation, various epoxy thermosets formulations, based on epoxidized soybean oil (ESO) and tannic acid (TA), were synthesized by adjusting the initial ratios of epoxide:hydroxyl groups (epoxy:OH). These formulations were subsequently applied onto carbon steel substrates and subjected to thermal curing at moderate temperatures (170 °C) to evaluate their anti-corrosion effectiveness using electrochemical impedance spectroscopy (EIS). The examination of the total impedance values derived from EIS Bode diagrams (>106 Ω) revealed a notable anti-corrosion efficacy that endured over several months of immersion in 3.5 wt% NaCl solutions. In addition to electrochemical assessment, a rheological analysis was conducted to determine the optimal curing temperature for each formulation and to track the evolution of their mechanical properties throughout the curing process. Furthermore, the progression of corrosion at the coating-metal interphase was quantified using samples featuring artificially created notches to facilitate rapid water penetration, reaching the protected surface. Moreover, cross-cut and pull-off adhesion tests were conducted on coatings cured with various epoxide:hydroxyl ratios, yielding exceptional results on carbon steel substrates. Overall, a great potential for anti-corrosion protection has been demonstrated on the developed fully bio-based coatings with tuneable mechanical properties, regarding the initial component ratio, to reach the specific requirements for specific applications.

Comparative analysis of microdamage-affected chloride transport in concrete under static and dynamic hydraulic pressure

Concrete structures in marine environments frequently encounter the adverse impacts of hydraulic pressure, leading to a decrease in their durability. This study aims to conduct a comparative analysis of the internal microdamage in concrete when subjected to static and dynamic hydraulic pressure of equal intensity, and to examine the influence of such damage on chloride transport. By employing potentiometric titration, MIP, N2 adsorption, and AFM tests, the chloride concentration, pore structure parameters, and microscale elastic modulus of concrete under static and dynamic hydraulic pressure were analyzed. The results indicate that dynamic hydraulic pressure accelerates chloride transport in concrete. Compared with static hydraulic pressure, dynamic hydraulic pressure — sustained at the same intensity—results in an elevated threshold pore size along with an increased most probable pore size of the concrete. Furthermore, dynamic hydraulic pressure induces the expansion of microcracks, consequently decreasing the microscale elastic modulus of concrete. The use of mineral admixtures can effectively mitigate the damage evolution of concrete microstructure subjected to dynamic hydraulic pressure. Besides, a model is developed for relative chloride diffusion based on the principle of energy conservation and from the evolution law of the microscale elastic modulus gleaned from AFM tests. Through calculations, it can be found that the crack propagation rate and the decline rate of the relative chloride diffusion coefficient Df1Df2 increase markedly when dynamic hydraulic pressure intensity surpasses 40,000 Pa. The propagation of the crack length is moderated by a larger initial crack width.

Self-healing concrete with a bacteria-based or crystalline admixture as healing agent to prevent chloride ingress and corrosion in a marine environment

Innovative solutions are needed to improve the durability of concrete structures in marine environment. Bacteria-based agents (BAS) and crystalline admixtures (CA) are explored as healing agents to enhance chloride resistance and prevent corrosion. Healing of 100 μm and 300 μm wide cracks was investigated, in combination with two conditioning methods. Either the samples were subjected to wet/dry cycles for 3 months before exposure (“healed”), or they were directly exposed to artificial seawater after crack creation (“unhealed”). After 12 months of submersion, BAS reduced chloride ingress even in the presence of cracks but showed limitations in preventing corrosion in cracked samples. In contrast, the CA series demonstrated a reduction in chloride ingress in both uncracked and cracked concrete and effectively prevented reinforcement corrosion in healed samples and samples with cracks of 100 μm. This highlights the potential of customized self-healing solutions to improve concrete durability in marine environments.

Language model enhanced surface chloride concentration determination for concrete within splash environment based on limited field records

Chloride ion is severely harmful to reinforced concrete (RC) structures in marine environments. For maintaining the durability and safety of the designed RC structures, the determination of chloride ion concentration on concrete surfaces is critical. Currently, surface chloride ion concentration can be determined using empirical formulas and machine learning (ML) approaches. However, these approaches only rely on the numerical information within field records, disregarding valuable semantic and background information in the records, leading to low accuracy. Meanwhile, in splash environments, it presents a significant challenge to obtain chloride ion concentration records due to the complex environment and high costs involved. Therefore, based on limited field records of surface ion concentrations in splash environments, and utilizing a state-of-the-art language model (LM), this study proposes an LM-based information generation (LMIG) model to improve the accuracy of determination of surface chloride concentrations on RC structures. This paper utilizes the numerical and semantic information in 70 sets of field records to fine-tune the LMIG model and generates 200 sets of high-quality records. These records are then used to train ML algorithms for predicting chloride ion concentrations on concrete surfaces. After conducting comparative research, it was found that incorporating records generated by the LMIG model significantly enhances the accuracy of the ML algorithm. Specifically, the predictive accuracy using the random forest algorithm increased by 33.1%. Furthermore, this paper also conducts a comparative study on the LMIG model and the generative adversarial network (GAN)-assisted data-driven method. The results demonstrate that integrating semantic and numerical information into the LMIG model shows significant advantages in enhancing ML algorithms’ accuracy.

A hybrid method for bond-slip behavior of reinforcement rebar in steel-polypropylene hybrid fiber reinforced concrete structures in marine environments

Fiber-reinforced concrete is an advanced class of construction materials that display higher mechanical and durability performance, but limited information is available on the bond behavior of reinforcement rebar in steel-polypropylene hybrid fiber reinforced concrete (SPHFRC) in marine environments, which produce crack states commonly seen in reinforced concrete structural components. In this study, a hybrid method for predicting the bond response behavior of SPHFRC under monotonic and cyclic loading was developed. The proposed method combining mechanical-driven model and generative adversarial networks (e.g., GAN) method. Experimental databases were constructed. Two empirical models were developed. The GAN method enhanced its prediction accuracy through adversarial training support by database and hyper-parametric analytics. Finally, to verify the accuracy and effectiveness of the developed model, a total of 65 SPHFRC specimens under cyclic loading were conducted. The comparison shows that this model can reproduce the corrosion-induced bond deterioration of SPHFRC. The model can also capture the cyclic bond degradation of SPHFRC and other types of ultra-high-performance concrete with an acceptable range.

Analysis of influencing factors of penetration mechanism and vertical bearing characteristics of monopile in calcareous sand: Laboratory model testing and in-situ testing

The construction of islands and reef engineering structures in marine environments has been a hot topic in recent years, and calcareous sand, which possesses unique physical properties, is widely distributed on islands and reefs. Due to the properties of calcareous sand, engineering problems such as pile slipping while driving and a low bearing capacity during service can occur. To address the key problem of pile‒soil interactions in calcareous sand foundations, laboratory model and in situ tests were conducted, accounting for factors such as impact energy, relative density, pile-forming method, and pile aspect ratio. First, the penetration mechanism of hammered piles in calcareous sand was studied. Then, the differences in vertical bearing characteristics between hammered and pre-embedded piles under different conditions were explored. The pile driving test results showed that a higher impact energy and lower relative density are more conducive to pile sinking. Moreover, as the number of hammer drops and dynamic penetration resistance increase with increasing burial depth, the pile tip resistance is the main factor limiting pile penetration in calcareous sand. The vertical static loading test revealed that particle breakage accelerates soil redistribution around the pile and that compaction enhances the bearing capacity of the pile. The pile aspect ratio, relative density and pile-forming method also play major roles in the vertical bearing capacity of piles in calcareous sand. In addition, the skin friction of a pile rapidly increases to the ultimate value along a multisegment trend of polyline functions. Similarly, the pile tip resistance rapidly increases at the initial loading stage, exhibiting the behavior of an end-bearing pile. The in situ test results indicated that the pile penetration depth in coral calcareous sand is an important factor affecting the bearing capacity.

Construction and Curing Behavior of Underwater In Situ Repairing Coatings for Offshore Structures.

The development of polymeric materials for the repair and reinforcement of damaged sites in water has many practical applications, especially in ocean engineering. However, it is difficult to construct an anticorrosion coating in water. In addition, curing kinetics, which are the key to enhance the performance of coatings, seem to hardly be observed and regulated in an underwater condition. Herein, a novel underwater in situ repairing coating was prepared. Meanwhile, electrochemical impedance spectroscopy (EIS) was applied to observe its curing behavior underwater. Adhesion tests showed that the coatings cured underwater had good adhesion to different substrate surfaces and the ideal ratio of curing agent to epoxy resin was 0.6. Long-term anticorrosive tests demonstrated that the coatings had an excellent anti-corrosion performance. The viscosity changes in different curing stages were well reflected by frequency response characteristics from Bode and Nyquist curves by EIS. Two equivalent electrical circuits were selected to simulate the impedance date at the initial and final curing stage. A formula was put forward to evaluate the curing degree during the curing process. Finally, the effects of temperature and the ingredient ratio on the reaction rate and curing degree were also investigated here. This underwater in situ repairing coating may find applications in many offshore engineering structures in marine environments, and the EIS technique has attractive development and application prospects when observing the curing information of thermosetting resin systems under special circumstances.

An experimental investigation on mitigating cracks and augmenting the endurance of concrete structures in marine environment by bio-mortar immobilised with halophilic bacteria

In coastal areas, built structures encounter hostile conditions and forces that can cause them to deteriorate over time owing to saltwater exposure, tidal forces, reinforcement corrosion, and freeze–thaw cycles. Early age cracks in such structures accelerate the rate of deterioration, and the current research focuses on alleviating such threats. This paper evaluates the performance of a self-healing mortar made by encapsulating expanded perlite with the bacterium Halobacillus Halophilus MCC2188. Mortar cube specimens of size 70.6 mm × 70.6 mm× 70.6 mm were prepared with cement: fine aggregate in 1:3 ratios. A 10% volume of the fine aggregate fraction was substituted with the expanded perlite immobilised with bacterial spores and nutrients. The expanded perlite aggregates were coated with sodium silicate and cement solution to protect the spores from the nonconducive environment. The specimens were subjected to fully and partially submerged marine water curing. The mechanical properties and self-healing potential were evaluated, and the precipitated polymorphs in completely healed cracks were identified and examined by characterisation techniques such as XRD, FEGSEM, FTIR, and TGA-DTG. The marine bacterium under investigation can tolerate the high salt concentrations commonly found in seawater and saline marshy soil and produce calcite through the metabolism of organic compounds, making it a suitable microorganism for self-healing applications. Crack widths of up to 0.84 mm and 92.79% average strength recovery were achieved in 56 days post-cracking, and the pace of healing was quicker in partially submerged curing conditions. The results showed improved self-healing, strength regain and mechanical strength and proved to be an efficient tool for enhancing the endurance of biomortar in severe marine exposure conditions.

A hybrid beam system of aramid-fibre-reinforced concrete and high-strength concrete

ABSTRACT This paper investigates the flexural behaviour of hybrid reinforced concrete (RC) beams having aramid fibre reinforced concrete (AFRC) in the tension zone and high-strength concrete (HSC) in the compression zone. In two series of experimental investigations, the depth of AFRC layer and the concrete strength in the compression zone were varied. The hybrid beams were tested in series 1 to explore the effects of the depth of AFRC layer on load-carrying capacity and flexural toughness. The effects of compressive strength of the concrete in the top half of the hybrid beams on load-deflection behaviour, failure mode and cracking pattern were studied in series 2. The experimental results reveal that the use of AFRC only in the bottom half of the beam enhanced load-carrying capacity and flexural toughness by 62.44% and 87.66%, respectively, compared to the control specimen with no AFRC. The hybrid beam with AFRC-HSC exhibited 5% higher load-carrying capacities, 45% higher ductility and better cracking behaviour than the conventional RC beam. These enhanced structural performances are beneficial for specific purposes such as structures in marine environment where rebar corrosion is the main concern, or structures under extreme loadings where high ductility is required.

Long-term shear performance of concrete beam with carbon fiber-reinforced composite grid stirrups under sustained loadings and seawater immersion

Using carbon fiber-reinforced composite (CFRP) grid stirrups to replace traditional steel stirrups in reinforced concrete (RC) beams can effectively improve the corrosion resistance of structures in marine environments. In this study, the durability of RC beams with CFRP grid stirrups under the coupled effects of sustained loads and immersion in seawater was studied. The sustained loads were set at 24% and 48% of the ultimate bearing capacity of the RC beam, and the specimens were immersed in artificial seawater at room temperature for 90 days, 180 days, and 360 days, respectively. The crack load and shear capacity of the beam were measured at the scheduled time. The initial stiffness of the beam decreased as the immersion time increased, and the higher the sustained load was, the lower the initial stiffness of the conditioned beam. The contribution of the CFRP grid stirrup to the shear load capacity after the cracking load was reached was more significant than that before. The effects of the 48% sustained load on the ultimate tensile strain of the CFRP stirrup were more significant than those for the 24% sustained load. Both immersion and sustained loading improved the cracking load and shear capacity of the beam, and the contribution of sustained loading to the shear capacity decreased as the immersion time and the sustained load level increased. Equations were proposed for predicting the shear strength of RC beams with CFRP grid stirrups under sustained loading and seawater immersion.

Measurement plan targeting the accuracy of calibrated chloride ingress model for concrete structures in marine environment

Surface chloride concentration (CS) and chloride diffusion coefficient (DCl) are key parameters for durability assessment of concrete structures in marine environment; they are time-varying and highly dependent on the exposure condition. To reasonably model their behaviors at a specific location, durability measurement data are often needed to calibrate the apparent chloride ingress model based on Fick’s second law. In view of the significant variability of measurements and the bias of chloride ingress model, it remains unaddressed how to formulate a measurement plan to make the calibrated model achieve the required accuracy. This paper first establishes the probabilistic time-dependent models of CS and DCl with both sample variance and model bias considered, and then introduces the Bayesian method to update the two models using measurement data. By assuming realistic models of CS and DCl and comparing them with updated ones, the effectiveness of Bayesian updating method is demonstrated, and the key factors affecting the updated model accuracy are discussed, including prior estimate of parameters, model bias and measuring times. On this basis, a determination method of measurement plan targeting the calibrated model accuracy is proposed, which works for both Bayesian updating and linear fitting for model calibration. And finally numerical examples are presented to show the validity of the proposed method. The sample size obtained by the proposed method is exact for linear fitting and slightly more than required for Bayesian updating.

Hydroelastic analysis of offshore floating photovoltaic based on frequency-domain model

This paper presents a frequency-domain model for analyzing the hydroelastic response and the vulnerable area of floating photovoltaic structures under wave action. The structure is discretized into an array of modules connected by equivalent elastic beams, while the boundary element method is employed to solve the scattering and radiation problems of the modules. The structural stiffness matrix is assembled by employing coordinate transformations and matrix reorganization techniques. The hydrodynamic matrix and the structural stiffness matrix are combined to establish the frequency-domain motion equation for describing the flexibility of the structure. The maximum gradient index is introduced to evaluate the dynamics issues of floating photovoltaic structures. The vulnerable area of the structure is assessed using the equivalent stress based on the von Mises stress theory. The proposed numerical model is validated by comparing the results with benchmark experiment as well as classical numerical model results. With this method, the hydroelastic response of a 300m×300m offshore floating photovoltaic is investigated. The displacement and internal force of the structure under various wave conditions is analyzed. This work can deepen the understanding of the hydrodynamics of floating photovoltaic structures in marine environment.

Moisture transports in high-cycle compressive fatigue-damaged concrete

Concrete structures in marine environments, e.g. bridges, usually undergo fatigue loads induced by vehicle transportations. Fatigue loads may lead to growth of micro-cracks in concrete which would initiate the additional transport channels and thus accelerate the penetration of moisture and some other aggressive agents into concrete This paper presents an investigation on the moisture transports in fatigue-damaged concrete. Axial compressive fatigue tests were conducted to obtain concrete with uniform compressive fatigue damage and residual strains were used as indexes to estimate the fatigue damage degrees of concrete. Water absorption and air drying tests were subsequently designed and carried out on fatigue-damaged concrete. Test results showed that the absorption rate increased with the residual strain and moisture could evaporate out of the exposed surface more easily of fatigue-damaged concrete than non-damaged concrete, which indicated that degradation of impermeability performance of fatigue-damaged concrete. In addition, prediction model of moisture transport in fatigue-damaged concrete was developed based on assumption of fictitious crushing band, and the accuracy of model was verified based on experimental results. The moisture transports in gradient fatigue-damaged concrete were further investigated based on the validated model with two damage indexes, i.e. residual strain at the exposed edge and residual curvature. The numerical results showed that the moisture transport rates are slightly decrease by the increase of residual curvature as the residual strain at the exposed edge was fixed. As compared to residual curvature, the rates of moisture transport in gradient fatigue-damaged concrete were more sensitive to the residual strains at the exposed edges.

Experimental Investigation and Numerical Model for Chloride Diffusivity of Long-Age Fly Ash Cement Slurry

Fly ash is a by-product of coal-fired thermal power plants and offers great potential for the use of resources. To effectively improve the durability of reinforced concrete structures in marine environment and achieve waste to treasure, fly ash is widely used as a pozzolanic material due to its long-hydration characteristics and effects of micro-aggregate, micro-filling and secondary hydration. In this study, both the experimental investigation and numerical simulation are carried out to study the chloride transport characteristics of fly ash cement paste. The variation in chloride diffusivity with fly ash content, water-to-binder ratio and curing age up to 360 days is studied via accelerated conductivity measurement, and it is found that the above three experimental variables have a significant impact on the chloride diffusivity. For the influence of the dosage of fly ash, the optimum dosage is 30%. By introducing specific rules for the particle distribution, the fresh fly ash cement paste is first made. Based on the volume change characteristics of fly ash and cement particles after hydration, the vector hydration model of fly ash cement paste is established by considering the water shortage effect caused by hydration layer interference. After the accuracy of this hydration model is verified by the results from third-party experiments, the random walk algorithm is proposed to calculate the diffusion coefficient of the reconstructed mineral admixture cement paste. By comprehensive comparison with the experimental results from the third-party and self-conducted experiments, the numerical model for predicting the chloride diffusivity of fly ash cement paste is verified.

Experimental based time-dependent reliability assessment of corrosion initiation for PC girders in frozen marine environment

Chloride induced corrosion is the main reason for the deterioration of concrete structures in marine environments, and the prediction of corrosion initiation life is one of the greatest challenges for preventative maintenance. To conduct a corrosion initiation assessment of PC girders in frozen marine environment and support preventative maintenance, a time-dependent reliability assessment method is developed. Long-term exposure experiments and in-house tests are combined to calibrate the chloride diffusion model, and then a probabilistic diffusion model is proposed based on the randomness of the key model parameters. Through the analysis of the target reliability index of corrosion initiation, the risk-function based time-dependent reliability assessment method is developed. Finally, a case study is introduced to illustrate the application of the proposed method. It is found that the surface chloride concentration on concrete structures in frozen marine environments increases at the beginning of service life and it tends to be stabilize when the service time is around 9–10 years. The age reduction factor of chloride diffusion can be described as the linear function of cementitious composition. The target reliability indices of corrosion initiation are suggested as 2.46, 1.50 and 1.13 for the referenced periods of 1, 10 and 20 years. The corrosion initiation life is very sensitive to the tensile stress level of concrete, and it decreases linearly with the increasement in tensile stress when the stress is not higher than 2 MPa.

Electrolytic co-deposition of Zn-ZnO and Zn-ZnO-CaCO<sub>3</sub> composite substrates on low-carbon steel

Conventionally employed zinc-rich paints and coatings for marine corrosion protection of steel still comprise environmentally unfriendly compounds such as zinc phosphate. This paper is focused on developing eco-friendly zinc ternary composite coatings of Zn-ZnO-CaCO3 utilizing CaCO3 additives derived from tympanotonus fuscatus (periwinkle) shell and calcareous eggshell respectively on low-carbon steel using electrodeposition technique. This is aimed at improving not only the surface corrosion resistance of steel structures in marine environment but also the sustainability of raw materials and minimal environmental pollution. Corrosion studies of uncoated and coated steel samples in simulated marine environment were done using linear polarization technique. Results obtained suggested that CaCO3 (i.e., calcareous eggshell) additive in the composite coating significantly improved the corrosion performance of the substrate. Steel coated with calcareous eggshell additive displayed superior corrosion performance having highest polarization resistance, Rp (156090 Ω), lowest corrosion rate, CR (0.01 mm/year) and highest coating efficiency, Ceff (97%) as against those of uncoated, zinc oxide, and tympanotonus fuscatus shell additives after 30 minutes deposition time. Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) results of selected developed coatings indicated presence of a homogeneous surface morphology and a significant amount of calcium in the calcareous eggshell coating.

Electrical resistivity tomography results analyzed with two inversion methods to determine chloride profiles on BFS concrete having very high electrical resistivity

Non-destructive evaluation techniques are increasingly used for the investigation of reinforced concrete structures in marine environment. In this paper, the possibility of evaluating chloride profiles by Electrical Resistivity Tomography (ERT) on Blast furnace slag (BFS) concrete at a long curing period so having high electrical resistivity was studied. This was carried out by monitoring the chloride profile for two 6-years old concretes (with and without slag) during a diffusion campaign using a Non-Destructive Evaluation (NDE) methodology. The methodology is based on determining the electrical resistivity profiles by carrying out surface apparent resistivity measurements submitted to two different inversion processes. The resistivity profiles are then converted to chlorides profiles using calibration curves. The chlorides profiles were also compared by those assessed by Destructive Evaluation (DE) at three different exposure periods, which displays a high similarity between DE and NDE profiles.