Chloride Ion Attack Research Articles

Insight into the dynamic evolution of competitive interaction between chloride and sulphate ions in cement-based systems: Effects on chloride diffusion and binding

The dual attack of chloride and sulphate ions is accompanied by the dynamic competitive interaction, yielding a non-negligible influence on their penetrations. Treating this interaction as a steady behaviour will underestimate the ionic ingress and then, overestimate the lifespan of concrete structures. In this study, the evolution of competitive interaction and the associated effect on the chloride diffusion and binding capacity have been investigated by comparing the exclusive chloride and the combined chloride-sulphate attacks. The experimental results disclose that the competitive interaction displayed a dynamic feature. Specifically, the competitive-induced depressions on chloride diffusion and binding capacity evolved first and then appeared to decay after reaching a threshold. Moreover, this competitive interaction was positively related to the w/c ratio and the environmental SO2-4/Cl- ratio. As the slag dosage increased from 0 % to 50 %, the competitive interaction-induced depression upon the free chloride content decreased steadily. However, the inhibition efficiency of the binding capacity decreased first as the slag dosage increased to 20 % and then, evolved significantly with the further increase through 20 % to 50 %. Furthermore, multifactor models are established with good applicability, to respectively predict the effect of this competitive interaction on the diffusion and binding of chloride ions.

Scalable nano-crystallization approach over multiple passivation behavior for Fe-based amorphous coating under chloride exposure

Structure-aware complicated Fe-based amorphous coating induced by scalable nano-crystallization approach proved influential in this work. The integration of experimental and mathematical findings uncovered that the dual nanocrystalline phases, interacting within the amorphous matrix of the coating subjected to annealing at 893 K, demonstrated the most superior electrochemical performance against chloride ion attack. At this singularity temperature, compositional intricacies were strengthened by structural relaxation, a consequence of the compatible collaboration of chemical constituents. The categorization of the vacancy-triggered point defects model (VR-PDM) indicated that the involvement and subsequent collapse of oxygen vacancies played a pivotal role in governing the multifaceted passivation behavior. A circulation of film spatial extension evaluated by d′-parameter in assistance with diffusion coefficients D of oxygen vacancies provided the direct evidence that reliable nano-crystallization strategy can reach a critical safety point against corrosion degradation. The total adaptive contribution of passivity to corrosion attack can be beneficial from the precise segmentation of surficial positions superimposed by target metallic atoms in competition with Cl- ions.

Corrosion behavior of HVOF sprayed 304 stainless steel coating on 6061 substrate in 3.5 wt% NaCl solution

This study aimed to improve the corrosion resistance of lightweight material surfaces by applying a 304 stainless steel coating (304SSC) onto 6061 aluminum alloy using high-velocity oxygen-fuel (HVOF) spraying. The phase composition, microhardness, microstructure, and long-term corrosion behavior of the HVOF-sprayed 304SSC in 3.5 wt% NaCl solutions were analyzed through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and an automated micro-hardness testing system. The findings indicated that the corrosion resistance of the coatings improved as the number of deposited layers increased. Moreover, the coatings that displayed the highest resistance to chloride ion attack in long-term immersion experiments also effectively prevented galvanic coupling. The enhanced corrosion resistance was attributed to reduced porosity, increased densification, and enhanced mechanical stability of the coatings.

Passivation of cold-sprayed zinc-coated steel bars in simulated concrete pore solution

Hot-dip galvanized coating is proved to be effective in preventing chloride ion induced corrosion on steel bars, however, highly-toxic substances generated during the plating process seriously pollute the surrounding environment. Cold-sprayed zinc as an environment-friendly technology is an alternative to the hot-dip galvanized technology, but it has not been applied to steel bars in the alkaline environment of concrete. This study first fabricated the cold-sprayed zinc-coated steel bars, and then investigated the influences of Ca2+ concentration and pH on the passivation of zinc-coated steel bars in the simulated concrete pore solutions through electrochemical tests, microstructure examination, and element composition analysis. The experimental results show that passive film can be generated on the surface of cold-sprayed zinc-coated specimens in the simulated concrete pore solutions with pH = 12.5 and Ca2+ concentration above 0.8 g/L, but Ca2+ concentration determines the density and quality of the passive film. The passive film can resist the attack of chloride ions up to 0.2 mol/L. Compared with hot-dip galvanized coating, more large-sized and compacted crystals are generated on the surface of cold-sprayed zinc coating. Thus, it is feasible to apply cold-sprayed zinc technology to provide corrosion protection for steel bars in the concrete.

Experimental study of corrosion effects on pulling force of hook bars in external beam-column connections

The external beam-column connection in concrete structures is particularly important because it is necessary to secure the reinforcement bars of the beam that are embedded within the column, which are often formed as a 90° hook. The attack of chloride ions is also one of the most dangerous damages that affect constructions and reduce their service life. Hence, it was necessary to study the effect of corrosion resulting from chloride ion attack on the strength of hook bars. To achieve this purpose, 26 specimens were designed with various variables, including the corrosion level of the reinforcement bars, compressive strength of the concrete, specimen loading, and the spacing between the stirrups relative to their diameter (S/D). The specimens were subjected to accelerated corrosion in the laboratory using the current density method by applying 0.35 mA/cm2 for 21 and 58 days. The experimental results showed that corrosion of the reinforcing bar in the joint weakens the mechanical behavior of rebars by reducing their strength and the bond between them and the concrete. The effect of the compressive strength of the concrete, specimen loading, and S\\D on the hook pulling force for corroded and non-corroded specimens has been observed, and they also affected the determination of the level of corrosion. Equations have been proposed to develop Faraday's law and determine the pulling force of a hook bar. The proposed equations yielded results that closely matched those from the experimental test.

Study of Reinforced Concrete with the Addition of Pozzolanic against the Penetration of Chlorides through Electrochemical Impedance Spectroscopy

The present work analyzes the behavior in terms of corrosion resistance of three reinforced concrete formulations over a period of 1 year. The samples were subject to a monitoring methodology using the Electrochemical Impedance Spectroscopy (EIE) technique, working only with the real component over time. Three mixtures were used, one conventional without pozzolanic addition (REF) and two others with pozzolanic additions, rice husk ash (RHA) and metakaolin (MK). Prototypes were created and exposed to the action of a 165 g/L NaCl sodium chloride solution. The characterization of the materials was carried out by determining the chloride diffusion profile (ASTM 1556), analyzing images using tomography and with the support of analytical techniques such as X-ray fluorescence and X-ray diffraction. The monitoring methodology using EIE demonstrated the positive effect of the insertion of pozzolans, rice husk ash (RHA) and metakaolin (MK) in delaying the process of chloride diffusion in the concrete, resulting in greater resistance to corrosion. The EIE also showed that the active mineral addition in concrete, resulting in aluminum-silicic composition (MK), had a predominant protective effect on the steel/concrete interface against the attack of chloride ions.

The adsorption and diffusion behavior of chloride in recycled aggregate concrete incorporated with calcined LDHs

Recycled concrete aggregate (RCA) is an important form for reusing of waste concrete. However, the presence of corrosive ions, specifically chloride ions, which are absorbed on the surface of RCA or infiltrated from the external environment, significantly affects the mechanical performance and durability of recycled aggregate concrete (RAC). This paper aims to suppress the erosion and diffusion of chloride ions in RAC by adding calcined layered double hydroxides (LDOs), utilizing the restructuring and anions exchange properties of LDOs. The dissolution ratio of chloride ions carried by RCA and the adsorption efficiency of LDOs on the leaching ions were analyzed using the silver nitrate titration method. The maximum chloride adsorption capacity of the LDOs is 31.052 mg/g. Additionally, the inhibitory effect and mechanism of LDOs on chloride ion attack were detailed evaluated by the techniques combining mercury intrusion porosimetry (MIP), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM and EDS), rapid chloride migration coefficient method (RCM), and electrochemical impedance spectrum. The results indicate that LDOs exhibit a good adsorption effect on chloride ions leaching from RCA, and the adsorption efficiency is negative correlation with the pH value. Furthermore, the small size effect of LDOs plays a filling role in the pores of concrete, increasing the compactness and penetration resistance of chloride ions of RAC. This work provides a promising approach to enhance the mechanical and durability properties of RAC by incorporating with LDOs utilizing its chloride ion capture feature and nano-filling effect. And the findings of this research can also be extended to the use of LDOs for treatment of other corrosive anions, such as SO42− and CO32− in RAC, demonstrating its applicability in a broader context.

Evaluation of Chloride Ion Attack in Self-Compacting Concrete Using Recycled Construction and Demolition Waste Aggregates

Construction and demolition waste (CDW) destined for recycling companies has great potential for use in civil construction, since it gives rise to recycled aggregates of different particle sizes that can be used in concrete. However, there is a lack of studies on the durability of concrete produced with recycled aggregates from CDW. This study analyzed the influence of incorporating recycled aggregates from CDW, sand, and gravel on the durability parameters of SCC mixtures, with and without the addition of metakaolin (MK), when subjected to two exposure conditions: outdoors and in cycles of attack by chloride ions. Five mixtures were produced: reference SCC, with natural sand and gravel; SCC with recycled sand and gravel; SCC with recycled sand and gravel and the addition of 10% MK; SAC with recycled sand, natural gravel, and the addition of 10% MK; and SCC with natural sand, recycled gravel and the addition of 10% MK. The water/binder ratio was kept constant for all mixtures and the additive dosage was adjusted according to the variation in the use of aggregates. The mechanical and durability properties were assessed using axial compressive strength, ultrasonic pulse velocity, chloride penetration, chloride ion diffusion, and electrical resistivity tests. The results showed the feasibility of using recycled aggregates from CDW in SCC. The addition of MK significantly improved the performance of SCC using these aggregates. The mixtures with added MK showed a low risk of corrosion and high resistance to chloride ion penetration, and, under highly aggressive attack conditions, it was observed that the chloride ions did not exceed the minimum cover thickness recommended for reinforced concrete structures. The addition of MK to the mix with recycled aggregates caused an 84.6% reduction in the Cl− diffusion coefficient, there was also a 40.3% reduction in Cl− penetration and an increase of up to 156.14% in electrical resistivity compared to the mix with recycled aggregates without the addition of MK. The SCC mix with recycled sand and metakaolin stood out positively compared to the others, achieving an axial compressive strength similar to the reference mix (55.10 MPa). We, therefore, conclude that it is possible to produce such a mix with acceptable performance and ensure good behavior under aggressive environmental conditions.

Proposição de variação do cobrimento nominal das armaduras baseada na classe de agressividade ambiental (CAA) de exposição de concretos

Abstract The physical and chemical protection of steel reinforcement afforded by the cover is a consequence of the quality of the concrete and its thickness, with a long-term impact on durability and service life. This study proposed variations in cover based on environmental aggressivity class (EAC) of exposure considering concretes of prescribed compressive strength classes (C20/C25/C30/C40). To this end, concrete mixtures were subjected to accelerated testing in salt spray chambers or carbonation. Accelerated testing was kept for periods long enough to reach each EAC cover level. Thus, the effect of each EAC, from mild to severe, was determined on the physical and mechanical characteristics of each mixture. It was determined that the required reinforcement cover varied linearly with compressive strength. This denoted the possibility of using more than one class of concrete and cover for each EAC. It should be noted that the difference in required cover became greater when using concrete with a strength class higher than C30. Still, it was noticed that the chloride ions attack s was more severe than carbonation and was, for most of the test cases, the determinant factor in minimum cover thickness to ensure the desired durability.

Effects of rare-earth element Y content on the microstructure and properties of quinary Al–Ni–Zr–Co–Y high entropy metallic glasses

A series of quinary (Al1/4Ni1/4Zr1/4Co1/4)100-xYx (x = 16–28 at.%) high entropy metallic glass ribbons were successfully fabricated through the high-speed single roller melt-spinning method. The effects of rare-earth element yttrium content on the microstructure and performances of alloy ribbons were systematically investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), heat treatment, transmission electronic microscopy (TEM), atomic force microscopy (AFM) and electrochemical experiments. The microhardness of metallic ribbons was measured by Vickers hardness tester. Results show that the microstructure of the as-quenched alloy ribbons maintain the glassy state and the average microhardness value of each specimen can reach 488 HV0.1 or above. The surface morphologies of the as-spun ribbon samples exhibit the smooth surface with small roughness value of Ra = 0.115–0.150 nm. In the meantime, with the increase of Y content, the glass transition temperature can be detected in the DSC traces when Y content is over 22 at.%, and the crystallization onset temperature shifts to the lower temperature region, suggesting that the thermal stability of amorphous state in Al–Ni–Zr–Co–Y alloy ribbons has been weakened. The (Al1/4Ni1/4Zr1/4Co1/4)84Y16 alloy ribbons own the highest crystallization onset temperature (∼742 K). Adding appropriate yttrium element can enlarge the super-cooled liquid region and improve the glass-forming ability. In 3.5 wt% NaCl solution, the prepared alloy ribbons can maintain smaller corrosion current densities (∼10−8 A cm−2) than traditional Al-based amorphous alloys, 6061 Al alloy and other common structural steels. The X-ray photoelectron spectrometer results indicate that the passive film of equiatomic alloy ribbons is rich in oxides of Al, Zr, Co, and Y elements, which has excellent resistance to chloride ion attack. On the basis of all experimental results, (Al1/4Ni1/4Zr1/4Co1/4)84Y16 alloy ribbons can optimally combine outstanding corrosion resistance, superior thermal stability, and acceptable microhardness. The above research results lay a solid foundation for the composition development of high-performance high entropy metallic glasses.

Numerical study on the chemical and electrochemical coupling mechanisms for concrete under combined chloride-sulfate attack

Cementitious materials exposed to marine and saline environments are commonly threatened by a combined attack of sulfate and chloride ions. This study developed a numerical framework to investigate two combined coupling mechanisms of 1) coupled solid-liquid chemical reactions for competitive chloride-sulfate attack and 2) electrostatic multi-ion coupling effect on reactive-transport mechanisms. Various chemical reactions including sulfate attack with anhydrous calcium aluminates, secondary precipitation of expansive minerals, competitive binding, and calcium leaching have been quantified. The electrostatic potential caused by multi-ions coupling was solved according to constitutive electrochemical laws. After model validation, the chemical coupling mechanisms for solid-liquid reactions during competitive chloride-sulfate binding were investigated. On this foundation, the influence of electrostatic multi-ionic coupling effects on ionic transport and its interaction with chemical coupling were disclosed. It was found that neglecting multi-ions coupling effect would result in an underestimated chemical coupling strength in competitive chloride-sulfate binding.

Chemical Mechanisms Involved in the Coupled Attack of Sulfate and Chloride Ions on Low-Carbon Cementitious Materials: An In-Depth Study

This study aims to analyze the individual and combined chemical attacks of sulfate and chloride ions on cementitious materials and assess the efficiency of some selected additives (fly ash, blast furnace slag, and metakaolin) in countering this combined attack. This research is conducted in the context of construction in marine environments, where reinforced concrete structures are often subject to significant challenges due to early exposure to sulfate and chloride ions. This early exposure results in concrete expansion, cracking, and, ultimately, the corrosion of steel reinforcements. Nevertheless, the interaction between sulfate ions, chloride ions, and the cementitious matrix remains poorly understood. Previous research has drawn conflicting conclusions, with some suggesting that sulfate ions mitigate chloride attacks, while others have come to the opposite conclusion. During this study, experimental investigations were conducted by immersing powders obtained from crushed ordinary Portland cement (CEM I) paste specimens, as well as binary, ternary, and quaternary blends, in sulfate, chloride, and sulfate–chloride solutions over the course of 25 days at an early age. Results from different characterization techniques (thermogravimetric analysis, Fourier Transform Infrared spectroscopy, Raman spectroscopy, etc.) indicate that chloride ions delay the formation of ettringite, while the presence of sulfate ions accelerates the chloride attack by limiting the formation of Friedel’s salt. The Mercury Intrusion Porosimetry test confirmed these results by showing a pronounced increase in specimens’ porosity after exposure to solely sulfate after 25 days, compared to the ones exposed to both sulfate and chloride ions. Furthermore, the incorporation of multiple additives, particularly in ternary and quaternary blends, demonstrates the enhanced durability of the studied samples. This was confirmed by a Fourier Transform Infrared spectroscopy analysis, which indicated a delayed ettringite formation in these mixtures. This delay was further affirmed by the complete depletion of sulfate ions in the sulfate solutions upon contact with powders derived from the 100% CEM I paste.

An overview of corrosion behavior and contemporary management techniques of thermomechanically treated rebars in concrete structures

ABSTRACT The corrosion of reinforcement possesses a huge problem for our present infrastructure both in terms of human lives and monetary ground. Understanding the corrosion of thermomechanically treated (TMT) rebar in concrete structures is essential as it represents a large segment of reinforcement materials. In this review, we have tried to scrutinize this issue from different directions. The established corrosion model for rebar, especially for TMT rebar, has been examined. The main contributing factor for rebar corrosion is how passivation occurs and its disintegration in contact with aggressive ions. The effects of composition, microstructure, concrete-rebar interface, concrete type, and corrosion media on this phenomenon have been analyzed. We have realized that the exact time of chloride ion attack determines the effectiveness of the passive layer in inhabiting the corrosion initiation. A combination of suitable alloying and controlled thermomechanical treatment ensures corrosion resistant rebar. Concrete also plays an important role in corrosion prevention as it helps passivation step and stops aggressive ions from reaching the rebars. Finally, we have discussed some recent trends in corrosion management technologies and their effectiveness.

Determination of the chloride ion content in concrete under simultaneous chloride and sulphate ion attack

Determination of the chloride ion content in concrete under simultaneous chloride and sulphate ion attack

Impact of low temperature and NaCl attack on the fracture properties of engineered cementitious composites (ECC)

Engineered cementitious composites (ECC) is a potential reinforcement and repair material for hydraulic structures due to its excellent mechanical properties. However, the fracture properties of ECC under the coupling effect of low temperature and chloride ions attack are still unclear. In this study, fracture experiments were performed on ECC specimens under different working conditions (immersed in water and NaCl solutions for different time (0, 30, 60, and 90d) and undergoing different freeze-thaw cycles (0, 25, 50, and 100 cycles) in NaCl solution) at experimental temperatures of 20 °C and −20 °C. The relationship between the depth of chloride ions erosion and the nominal fracture energy was analyzed. The effect of the coupled of temperature and chloride ions attack on the fracture performance of ECC under different working conditions was investigated. The results showed that: Under the loading condition of −20 °C, the fracture parameters of ECC under NaCl solution immersion were all lower than those of the water immersion group, indicating that extravasated chloride ions negatively impacted ECC's fracture properties. When ECC was loaded at −20 °C, the initiation fracture toughness and unstable fracture toughness of ECC under NaCl solution immersion were lower than those of the water immersion group, but the fracture energy was larger than that of the water immersion group, and when the specimens were immersed for 90 days, the drop in the fracture energy of ECC loaded at −20 °C compared to 20 °C for the NaCl solution immersion group was 59.1% less than 62.7% for the water immersion group; While loading at 20 °C revealed a linearly declining relationship between erosion depth and fracture energy, loading at −20 °C revealed no discernible pattern. The crack initiation fracture toughness of ECC gradually decreased with the increase of the freeze-thaw cycles, but the specimens' crack initiation fracture toughness following NaCl freezing at −20 °C was consistently larger than that at 20 °C. Following 100 freeze-thaw cycles on the specimens, the increase in initiation fracture toughness at −20 °C compared to 20 °C for the water freeze-thaw group was 128.4% less than that of the salt freeze-thaw group, which was 135.8%, while the decrease in fracture energy was 19.9% less than that of the salt freeze-thaw group, which was 46.3%. It shows that the repair effect of ice on ECC after NaCl freeze-thaw cycles is stronger than that of water freezing at the low temperature.

Corrosion of hybrid alkaline cements in saline solution simulating evaporite rock – Effect of the Portland clinker content

Two hybrid alkaline cements (HAC) based on Portland clinker, ground granulated blast furnace slag (GGBFS), fly ash and sodium sulfate, as well as an alkali-activated GGBFS/fly ash blend and a Portland cement paste were exposed to a saturated saline solution for 70 days. The combined chemical attack of chloride, magnesium and sulfate ions and the associated changes of the phase assemblage of the materials were studied by X-ray diffraction, thermal analysis and spatially resolved X-ray fluorescence spectroscopy. The experimental results revealed dissolution of ettringite, C-N-A-S-H and calcite, and the formation of gypsum, Kuzel's salt and Friedel's salt; thermodynamic modeling indicated the formation of M-S-H. The resistance of the HAC against attack by the saline solution increased with Portland clinker fraction. The capacity of portlandite to maintain pH at values above 10 is found to be a major factor controlling the resistance of HAC against corrosion in the saline solution.

Exploring Exact Effects of Various Factors on Chloride Diffusion in Cracked Concrete: ABAQUS-Based Mesoscale Simulations

Chloride ion attack is a major cause of concrete durability problems, and existing studies have rarely addressed the effects of damage zones. In this paper, an improved mesoscale model including five phases was constructed using the finite element software ABAQUS to study the diffusivity of chloride ions in cracked concrete. It was found that the damage zone is negligible when the crack width is less than 50 μm, while the width and depth of the damage zone are about 15 times the crack width and 15% of the crack depth when the crack is greater than 50 μm. The results show that the diffusion of chloride is greatly influenced by the crack width, while it is little-influenced by the crack shape. Low water-cement ratio and adequate hydration of the concrete are also key factors affecting chloride diffusion. In contrast, regular rounded aggregates have a positive effect on reducing chloride diffusion compared to irregularly shaped aggregates, and this effect becomes weaker with increasing service time. In addition, the protective layer can effectively prevent the diffusion of chloride in concrete. Therefore, when designing marine concrete, efforts should be made to ensure that the concrete has a low water-cement ratio, adequate hydration, less cracking and a protective layer.

RACBase: A cloud-based database of recycled aggregate concrete durability

This paper presents the first universal cloud-based database of recycled aggregate concrete (RAC) durability, named RACBase. The database collects experimental data on the durability of RAC from published literature all over the globe. Each set of data consists of the literature source, materials information, and the unified test result. The resistance to chloride ion attack, carbonation, sulfate attack, and freeze-thaw for RAC is quantified by the passed electric charge, carbonation depth, compressive strength loss, and durability factor, respectively. Based on the web interface, RACBase provides the functions of searching, adding, acquiring, and storing data, and gives the statistical distribution of data for each durability test. Users can freely access RACBase at https://www.racbase.com and browse and upload their data after online registration. One illustration of building a machine learning model for predicting the chloride resistance of RAC is presented to show the potential application of the database. The extreme gradient boosting model shows superiority to the artificial neural network and random forest models with the R2 of 0.975, RMSE of 246.719, and MAPE of 0.081. RACBase enriches the way for users to conduct in-depth research on the durability of RAC and construct performance prediction models.

Study and Neural Network Analysis on Durability of Basalt Fibre Concrete

In order to investigate the law of basalt fibre to enhance the durability of concrete, this paper selects basalt fibre length as the main factor, supplemented by novel research methods such as neural networks, to study the rule of concrete resistance to multiple types of salt erosion. Tests have shown that large doses of mineral admixtures and basalt fibres can prolong the time that concrete is eroded by salt solutions; the age of maintenance has a small effect on the mechanical and durability of the concrete; the increase in length of basalt fibres enhances the mechanical properties of the concrete, but weakens the durability. This is exacerbated by the mixing of fibres, but the increase is not significant; the effect of length on concrete resistance to mass loss, corrosion resistance factor of compressive strength, and resistance to chloride ion attack is ranked as follows: 6 mm > 12 mm > 18 mm > 6 mm + 12 mm > 6 mm + 12 mm + 18 mm. The opposite is true for effective porosity; the highest compressive strength corrosion resistance coefficient was found in the length of 6 mm, with an average increase of 6.2% compared to 18 mm, and the mixed group was generally smaller than the single mixed group. The average increase in chloride content was 25.1% for length 18 mm compared to 6 mm; the triple-doped L6-12-18 group was the largest, with an average increase of 33.9% in effective porosity over the minimum 6 mm group. Based on the data from the above indoor trials, artificial neural network models and grey cluster analysis were used to predict and analyse the data, and the prediction and categorisation results were accurate and reliable, providing a reference for subsequent studies.

Deterministic and probabilistic approaches for corrosion in RC structures: A direct proposed model to total service life predictions

In this paper the negative effects of the chloride ions attack in reinforced concrete (RC) elements have been studied. For this the vertical and horizontal chloride diffusivity has been treated by several models to identify the more relevant factor affecting the chloride concentration. The pitting corrosion has been treated to define the resistance losses of the shear forces and bending moments. An alternative deterministic/probabilistic procedure, by a direct and systematic new model, has been proposed to estimate the total time of service life for RC elements at the design phase. Several detailing configurations of steel bars in a RC beam, water/cement ratio and level of aggressiveness have been analysed to compare the model predictions. In this sense, this paper should provide useful results for analysts in terms of probability of failure for resistance losses and time of corrosion initiation. The goal is not only to provide practical results but also to evaluate the issue in a more modern risk analysis throughout the proposed prediction model.