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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"Chloride Diffusion"”.
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Durability of alkali-activated calcined clay - GGBFS concrete against carbonation and chloride diffusion
… through tests assessing the performance in chloride and carbonation-rich environments. The results show that the inclusion of GGBFS as a rich calcium source, notably improves the mortar microstructure and increases the pH of the pore solution, enhancing the carbonation resistance. Concretes …
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Evaluation of Chloride Diffusion in Concrete Using Bulk Diffusion Test and Scanning Electron Microscopy
… concern impacting the durability of concrete is chloride penetration in aggressive environments such as marine or coastal areas. In such environments, chloride ions can penetrate into the pores of concrete leading to the corrosion of embedded steel reinforcement which compromises the structural …
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Determination of chloride diffusion constants for concretes of differing water to cement ratios and admixtures
Reinforced concrete exposed to chlorides is subject to rapid deterioration once the concentration of the chloride ion in the concrete reaches a critical level to cause corrosion of the reinforcing steel. The chloride ion diffuses through concrete according to Fick's Law, which is a function of …
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Enhancing the service life of concrete exposed to chloride attack
… to enhance the durability of concrete exposed to chloride attack by means of two approaches: (i) to design sustainable concrete compositions and (ii) to apply suitable maintenance techniques consisting of electrochemical chloride extraction (ECE) and surface coating (SC) treatments. Subsequently, …
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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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Design and Development of an In-situ Chloride Migration Test
The predominant mechanism of transport of chloride ions into concrete is diffusion. The rate of diffusion is largely controlled by the chloride diffusivity or chloride diffusion coefficient of the concrete. The determination of this parameter requires a long test duration and, hence, migration test …
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Rapid assessment of the potential chloride resistance of structural concrete
This present study benchmarked the chloride resistance of concretes mixes at the limit state of BS 8500-1:2006 using the newly published CEN TS12390-11. Of the three allowed methodologies, the immersion test was carried out. At least two water-cement ratios were produced for each mix design to …
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Behaviour of epoxy filled flat-face joints in concrete for wave energy converters
… an<br/>unfortunate better path for water and chloride penetration.<br/><br/>Phase II focused on the durability of epoxy bonded concrete in seawater. A prototype was made in accordance with one of the famous WECs and evaluated after two years of exposure in the marine environment. This …
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Development of low-clinker concrete: partial replacement of cement with calcined clay and limestone, based on selected African raw materials
… strength development, durability indexes, chloride diffusion characteristics, electrical resistivity, carbonation resistance, shrinkage, and potential for early age cracking. Overall, it can be concluded that the selected LC3 concrete mixes perform similarly or better than the reference …
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Role of cement content in determining resistance of concrete to reinforcement corrosion
… and resistance of concrete to carbonation-andchloride- induced reinforcement corrosion. Moreover, no data were found on the combined influences of crack width and cement content on resistance of concrete to reinforcement corrosion.Given this background, this study was designed to fill in many …
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Chloride penetration in concrete: evaluation of rapid conductivity methods and development of a service life prediction model for marine conditions
Chloride-induced corrosion is the predominant cause of loss of service life in reinforced concrete structures subjected to marine conditions. To protect reinforcing steel from the corrosive effects of external chloride ions present in these environments, a proper combination of concrete quality and …
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Corrosion Behavior of Corrosion-Resistant Steel Reinforcements in High and Ultra-High Performance Concrete in Chloride Attack Environments
… and ultra-high performance concrete (UHPC) in chloride attack environments. Additionally, this dissertation presents service life prediction and life cycle cost analysis of RC structures made with different types of concrete and reinforcements. Firstly, an experimental program was conducted to …
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An investigation into the relationship between surface concrete resistivity and chloride conductivity test
The chloride conductivity test (CCT) is a South African-developed Durability Index (DI) test used for the evaluation and quantification of the quality of concrete cover. It is also used as an input parameter for service life prediction (SLP) of RC structures in the marine environment, using a …
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Development of a new test protocol for the permit Ion migration test
Chloride induced corrosion of steel in concrete is one of the most common reasons for the deterioration of reinforced concrete in both marine and transportation structures. In order to assess the chloride penetration resistance of concrete, the common practice is to remove cores from the structure …
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Service life extension of reinforced concrete structures using hydrophobic impregnation
… 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 in the uncracked state, leading to an …
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Influence of Bridge Deck Concrete Parameters on the Reinforcing Steel Corrosion
Chloride induced corrosion of steel in concrete is one of the major forms of deterioration mechanisms found in reinforced concrete bridges. Early age corrosion damage reduces the lifespan of the bridges, which results in heavy economic losses. Research has been conducted to identify economic …
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Investigation on the Overall Performance of Recycled Concrete Affected by Alkali-Silica Reaction
… alkali-silica reaction (ASR) affected RCA on the chloride diffusivity (and thus corrosion initiation) of concrete. This work aims to appraise the durability performance of RCA concrete made of 100% coarse RCA, particularly two families of RCA selected (i.e., returned concrete RCA, demolished …
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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 development of empirical chloride-induced corrosion rate prediction models for cracked and uncracked steel reinforced concrete structures in the marine tidal zone
Empirical chloride-induced corrosion rate prediction models for cracked and uncracked reinforced concrete (RC) structures in the marine tidal exposure zone are proposed in this study. The data used to develop the models were obtained from parallel corrosion experiments carried out by exposing half …
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The Economy of Preventive Maintenance of Concrete Bridges Due to Corrosion
… maintenance measure are identified. Since the chloride induced corrosion is the major factor that dictates the service life of the steel reinforced bridge element, a refined equation for estimation of the diffusion coefficient of chloride ions into concrete is proposed. </p> <p>A Finite Element …
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