Search Results (7)

This paper presents a validated, data-driven framework for the sustainable rehabilitation of corrosion-damaged marine infrastructure, demonstrated through a comprehensive study on a historic coastal structure. The implemented three-phase methodology—integrating advanced condition assessment, evidence-based intervention design, and rigorous performance validation—successfully addressed severe chloride-induced deterioration. Diagnostic quantification revealed that 30% of the primary substructure was severely compromised, with chloride concentrations reaching 1.94% by weight (970% above the corrosion threshold) and half-cell potential mapping confirming a >90% probability of active corrosion in critical elements. Guided by this data, a synergistic intervention combining galvanic cathodic protection, high-performance coatings, and structural strengthening was deployed. Post-repair validation confirmed exceptional outcomes: a complete electrochemical repassivation (potential shift from −385 mV to −185 mV), a 97.3% reduction in chloride diffusion rates, a 250% increase in surface resistivity, and the restoration of structural capacity to 115% of design specifications. The framework achieved a 65% reduction in projected lifecycle costs while establishing a new paradigm for preserving marine infrastructure through evidence-based, multi-mechanism strategies that ensure long-term durability and economic viability. Full article

Self-healing polymer-based coatings have emerged as a new generation of adaptive protective materials capable of restoring their structure and function after damage. This review provides a comprehensive analysis of current strategies enabling autonomous or externally triggered repair in polymeric films, including encapsulation, reversible chemistry, and microvascular network formation. Emphasis is placed on polymer–inorganic hybrid composites and vitrimeric systems, which integrate barrier protection with stimuli-responsive healing and recyclability. Comparative performance across different matrices—epoxy, polyurethane, silicone, and polyimine—is discussed in relation to corrosion protection and biomedical interfaces. The review also highlights how dynamic covalent and supramolecular interactions in hydrogels enable self-repair under physiological conditions. Recent advances demonstrate that tailoring interfacial compatibility, healing kinetics, and trigger specificity can achieve repeatable, multi-cycle recovery of both mechanical integrity and functional performance. A representative selection of published patents is also shown to illustrate recent technological advancements in the field. Finally, key challenges are identified in standardizing evaluation protocols, ensuring long-term stability, and scaling sustainable manufacturing. Collectively, these developments illustrate the growing maturity of self-healing polymer coatings as multifunctional materials bridging engineering, environmental, and biomedical applications. Full article

Reinforced concrete structures in harsh environments are highly vulnerable to structural damage caused by rebar corrosion. However, there remains a critical shortage of high-performance, environmentally friendly repair materials that integrate both structural restoration and long-term corrosion protection functionalities to address this issue. To meet this demand, this study innovatively developed an eco-friendly, high-performance repair material using lotus leaf extract (LLE)-modified mortar and systematically evaluated its corrosion protection performance and mechanisms under chloride attack conditions. The primary chemical constituents of LLE include alkaloids and flavonoids, rich in polar functional groups such as O–H, N–H, and C–O. The LLE modifier increased the fluidity of fresh cement paste, thereby improving its construction workability. A low dosage of LLE modifier promoted cement hydration. When the LLE dosage was 0.2 wt%, the 7-day and 28-day flexural strengths of the LLE-modified mortar increased by 16.8% and 7.48%, respectively, compared to those of unmodified mortar, while the compressive strengths increased by 30.6% and 14.5%, respectively. The LLE-modified mortar demonstrated significant protection against chloride corrosion, effectively inhibiting rebar corrosion. Electrochemical corrosion results indicated that compared to unmodified mortar, the modified mortar containing 0.5 wt% LLE exhibited an 80% improvement in protection efficiency against chloride corrosion. These results demonstrate that an appropriate dosage of LLE modifier can simultaneously optimize the fundamental properties of mortar and provide excellent chloride corrosion protection. Therefore, LLE-modified mortar shows promising application potential in integrated repair and corrosion protection engineering for reinforced concrete structures. Full article

In offshore oil and gas extraction, riser pipes serve as the first isolation barrier for wellbore integrity, playing a crucial role in ensuring operational safety. Protective coatings represent an effective measure for corrosion prevention in riser pipes. To address issues such as electrochemical corrosion and poor adhesion of existing coatings, this study developed an underwater-curing composite material based on a polyisobutylene (PIB) and butyl rubber (IIR) blend system. The material simultaneously exhibits high peel strength, low water absorption, and stability across a wide temperature range. First, the contradiction between material elasticity and strength was overcome through the synergistic effect of medium molecular weight PIB internal plasticization and IIR crosslinking networks. Second, stable peel strength across a wide temperature range (−45 °C to 80 °C) was achieved by utilizing the interfacial effects of nano-fillers. Subsequently, an innovative solvent-free two-component epoxy system was developed, combining medium molecular weight PIB internal plasticization, nano-silica hydrogen bond reinforcement, and latent curing agent regulation. This system achieves rapid surface drying within 30 min underwater and pull-off strength exceeding 3.5 MPa. Through systematic laboratory testing and field application experiments on offshore oil and gas well risers, the material’s fundamental properties and operational performance were determined. Results indicate that the material exhibits a peel strength of 5 N/cm on offshore oil risers, significantly extending the service life of the riser pipes. This research provides theoretical foundation and technical support for improving the efficiency and reliability of repair processes for offshore oil riser pipes. Full article

This study focuses on the evolution of the Arousa Island Bridge, a critical infrastructure connecting, in northwestern Spain, the Arousa island to the Galician coast. Since its commissioning in 1985, the bridge has experienced damage due to corrosion, culminating in a major repair intervention in 2011 using hybrid galvanic cathodic protection. This repair was essential in addressing identified pathologies and ensuring the safety of the structure. In 2021, additional repairs needed to be completed, and a thorough study and testing campaign was conducted in 2023 which included the extraction of zinc anode samples from the bridge. The present work evaluates the effectiveness of the repair measures implemented since the intervention, with particular attention to corrosion risk and the durability of the cathodic protection system installed to mitigate corrosion risks in the reinforced concrete exposed to a harsh marine environment. A key aspect of this study is the correlation established between the indirect measurements utilized to evaluate zinc consumption within the cathodic protection system and the direct assessment obtained from the extraction of the anodes, which provides a tangible measure of this consumption. The calculated service life was updated with the measurement, and the integrity of the system was assessed. Full article

Weld surfacing is the process of applying a layer of metal to the surface of metal objects by simultaneously melting the substrate. As a result of this process, the metal content of the padding weld can be as high as several tens of percents. It is a method used to regenerate machine parts and improve the properties of the surface layer, increasing its resistance to abrasion, corrosion, erosion, and cavitation. It also supports the repair and creation of permanent protective coatings in the engineering, automotive, energy, and aerospace industries. This makes it possible to repair damaged parts instead of completely replacing them, saving time and production costs. Plasma surfacing technology is used for components that require high hardness and corrosion resistance under various environmental conditions. Plasma wire surfacing is not sufficiently presented and described in the current literature, which creates problems in determining the appropriate process parameters. The influence of variable plasma surfacing parameters on steel C45 significantly affects surfacing weld geometry, the dilution factor, and microhardness. Higher currents can increase the dilution factor, integrating more base metal into the weld pool, which may alter the chemical composition and mechanical properties of the weld. Variations in surfacing speed and heat input also affect the microhardness of the surfaced joint, with higher heat inputs potentially leading to softer welds due to slower cooling rates. Optimizing these parameters is essential to achieving desired surfacing weld characteristics and ensuring the structural integrity of C45 steel joints. This paper presents the influence of varying plasma surfacing parameters on the surfacing geometry, the dilution factor, and microhardness. The tests were carried out on a Panasonic TM-1400 GIII automated surfacing machine with CastoMag 45554S solid wire as the filler material. Flat bars of C45 steel were prepared, and then the variable parameters of the surfacing process were developed. Tests were carried out to determine the dilution factor, followed by microhardness measurements. The results showed a significant dependence of the effect of the parameters on the surfacing geometry and the dilution factor. Full article

This article reviews the literature related to the performance of fiber reinforced concrete (FRC) in the context of the durability of concrete infrastructures. The durability of a concrete infrastructure is defined by its ability to sustain reliable levels of serviceability and structural integrity in environmental exposure which may be harsh without any major need for repair intervention throughout the design service life. Conventional concrete has relatively low tensile capacity and ductility, and thus is susceptible to cracking. Cracks are considered to be pathways for gases, liquids, and deleterious solutes entering the concrete, which lead to the early onset of deterioration processes in the concrete or reinforcing steel. Chloride aqueous solution may reach the embedded steel quickly after cracked regions are exposed to de-icing salt or spray in coastal regions, which de-passivates the protective film, whereby corrosion initiation occurs decades earlier than when chlorides would have to gradually ingress uncracked concrete covering the steel in the absence of cracks. Appropriate inclusion of steel or non-metallic fibers has been proven to increase both the tensile capacity and ductility of FRC. Many researchers have investigated durability enhancement by use of FRC. This paper reviews substantial evidence that the improved tensile characteristics of FRC used to construct infrastructure, improve its durability through mainly the fiber bridging and control of cracks. The evidence is based on both reported laboratory investigations under controlled conditions and the monitored performance of actual infrastructure constructed of FRC. The paper aims to help design engineers towards considering the use of FRC in real-life concrete infrastructures appropriately and more confidently. Full article