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Showing 1 to 20 of 25 for “"chloride ingress"”.
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Assessment and prediction of chloride ingress and carbonation in patch repair mortars
… requirements, such as carbonation resistance and chloride resistance, are usually not considered despite the fact that they have a direct influence on the durability performance of concrete repair mortars. The widespread premature failure of patch repairs which meet the existing compressive …
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The influence of concrete mix composition and environmental exposure on long-term chloride ingress in concrete
The parameters influencing long-term chloride ingress in concrete structures exposed to different environmental conditions in South Africa were investigated, aiming at improving service life prediction models for reinforced concrete structures situated in marine exposure classes. Time-dependent …
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Durability of Cementitious Materials in Arctic Regions: Investigating Freeze-Thaw Damage and Chloride Ingress Diffusion Mechanisms
… challenges from freeze-thaw (F-T) cycles and chloride ingress due to seawater and deicing salts, resulting in surface scaling, spalling, and cracking. Climate change exacerbates these issues, particularly in high-latitude areas like Alaska, where rising temperatures lead to permafrost thaw and …
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Service Life Assessment of Harbor Structures - Case studies of chloride ingress into concrete and sheet piling corrosion rates
… of corrosion of the reinforcement due to chloride ingress. When the chlorides have passed through the concrete cover and reached the reinforcement, the passivating protection of the rebars is lost and the corrosion processes starts. When designing new concrete structures in marine …
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Chloride transport and chloride thresholdvalues-Studies on concretes and mortars with Portland cement and limestone blended cement
… media from the surrounding environment. Chloride initiated reinforcement corrosion is one of the major causes of deterioration of concrete structures. One conflicting issue is how replacing Portland cement with mineral additions influences chloride initiated reinforcement corrosion. This …
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Chloride Penetration Resistance and link to Service Life Design of Virginia Bridge Decks
… concrete (RC) bridge decks are exposed to chlorides from deicing salts. Chloride ingress in RC initiates corrosion of the reinforcing steel. The high costs of corrosion have sparked interest in service life design of bridge decks. This thesis characterized the exposure conditions of …
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Service life extension of reinforced concrete structures using hydrophobic impregnation
… development. Cracks provide preferential ingress paths for deleterious species such as chlorides and this leads to a reduction in the time taken for reinforcement corrosion initiation and thus reduces the service life of the structure. Most service life models also consider concrete only …
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Effect of Initial Surface Treatment Timing on Chloride Concentrations in Concrete Bridge Decks
… on concrete bridge decks as barriers against chloride ingress. In consideration of concrete cover thickness and the presence of stay-in-place metal forms (SIPMFs), the objective of this research was to determine the latest timing of initial surface treatment applications on concrete bridge …
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Integrity and effectiveness of standard preformed membranes placed on concrete bridge decks
… for almost three decades in order to prevent chloride ingress into concrete. However, the performance of these membranes have yet to be adequately evaluated. Therefore, this research was carried out primarily to evaluate the integrity and effectiveness of standard preformed membranes placed on …
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Assessing the influence of crack width on the durability potential of cracked concrete using the durability index approach
… study focused on the influence of cracks on the ingress of aggressive species (carbon dioxide and chlorides) into cracked concrete in comparison to uncracked concrete. The aim was to establish any correlations between the transport properties in uncracked and cracked concrete. Furthermore, in a …
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Transport and sorption phenomena in concrete and other porous media
… the effect of different cements and pozzolans on chloride ingress into concrete. <br> RI:3, The models established in RI:1 and P:1 are used to study the effect of curing conditions on chloride ingress in concrete. A drying period before exposure to chlorides is shown to decrease the penetration. …
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Computational Simulation of Chloride-Induced Corrosion Damage in Prestressed Concrete Bridge Girders
… analytical tools for the accurate simulation of chloride ingress, corrosion and mechanical damage (cracking) in the concrete, and for the evaluation of the impact of corrosion on the flexural and shear strength of bridge girders. First, an efficient and accurate analytical scheme is formulated to …
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Effect of Environmental Conditions and Structural Design on Linear Cracking in Virginia Bridge Decks
Chloride-induced corrosion of reinforcing steel is widely accepted as the primary cause of premature deterioration in concrete bridge decks (Brown, M.C., 2002). Since linear cracking in concrete cover can potentially accelerate chloride ingress to the depth of the reinforcing steel, there is reason …
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Comparative study on the behaviour of concrete reinforced with FRP and steel singly reinforced beams
… of the steel creates an environment prone to chloride ingress and carbonation. This leads to steel corrosion and internal stresses which further exasperates the problem. Fiber Reinforced polymers can be an alternative to steel reinforced because it is considered to be chemically inert, high …
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Ternary combination concretes using GGBS, fly ash & limestone: strength, permeation & durability properties
… properties (accelerated carbonation and chloride ingress) of the test concrete were also investigated. At 28 days, for low GGBS levels, the binary concretes gave reduced absorption properties compared to CEM I, while the reverse occurred at high level. The effect of the ternary concretes …
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A mechanistic approach For predicting the effect of various factors on partitioning between free and bound chlorides in concrete
The chloride-induced corrosion of reinforcing steel in concrete structures has become a widespread durability problem throughout the world. When concrete structures come in contact with chloride sources, the chloride ions will diffuse through the body of the concrete and ultimately reach the steel. …
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Durability Assessment and Service Life Prediction of Concrete in Extreme Aggressive Environment
… the performance of various concrete mixes for chloride resistance. The study focuses on establishing and developing correlations between chloride diffusion rates and concrete resistivity. By identifying these correlations and based on the target service life, the research aims to set …
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Behaviour of massive reinforced concrete sections in seawater
… has focussed on concrete degradation due to chloride ingress, corrosion of permanently submerged concrete is regarded as negligible due to the long-assumed apparent worst case of tidal or splash zone exposure. Around 350 specimens were tested with a further 200 exposed for further testing by …
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Alternative patch repair materials for rebar corrosion damage
… installing sacrificial anodes (at least for chloride contaminated concrete) and surface coating. In principle, if this process is correctly followed then the material requirements for a durable, non-structural repair would be to fill in the cavity created by removing contaminated concrete, …
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An analysis of the impact of chloride-induced corrosion on reinforced concrete structures in the port of Cape Town
… structures in the marine environment, where chloride ingress causes severe and widespread damage. These structures make up a substantial proportion of infrastructure globally and are costly to construct and require constant maintenance throughout their service life. For infrastructure owners …
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