| 1. |
- Boubitsas, Dimitrios, et al.
(author)
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An approach for measurement of chloride threshold
- 2013
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In: International Journal of Structural Engineering. - 1758-7328 .- 1758-7336. ; 4:1/2, s. 24-34
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Journal article (peer-reviewed)abstract
- Chloride induced corrosion is one of the major causes for degradation of reinforced concrete structures. One of the most important factors in this process is the critical chloride content (chloride threshold value) in the vicinity of the reinforcement that causes initiation of corrosion. In this work the development of a practice-related approach that includes specimen shape, preconditioning, corrosion measurement techniques, and calculation concepts, for determining the critical chloride content are presented. The results in this study showed that the presented approach for determining chloride threshold values functioned fairly well, and suggestions for further improvement are proposed.
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| 2. |
- Dias Ferreira Da Silva, Nelson, 1978, et al.
(author)
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Chloride profiles along the concrete-steel interface
- 2013
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In: International Journal of Structural Engineering. - 1758-7328 .- 1758-7336. ; 4:1/2, s. 100-112
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Journal article (peer-reviewed)abstract
- The composition and microstructure of the concrete-steelinterface influences the critical chloride content for initiation of pitting corrosion and these characteristics may differ from those of the bulk concrete. This paper describes the development of a methodology for chloride profiling along the interface by means of LA-ICP-MS. For semi-quantitative analysis, microstructure characterisation of the pitting positions and distribution and composition of the corrosion products, SEM-EDS and XRD techniques wereemployed. The results indicate that along the interface a range of chloride levels can be expected. These varied between 0.15–1.5 wt% of concrete with higher levels around the active corrosion sites. Good agreement has been foundbetween the results from LA-ICP-MS and EDS techniques. Interface defects strongly influenced the pitting corrosion. Several Fe(III) oxy-hydroxides accumulated at the aggregate-paste interface and in air voids at the cementpaste. XRD analysis suggested the presence of akaganeite and FeCl2 (rokuhnite).
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| 3. |
- Ismail, Eman J.
(author)
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RC skew slabs behaviour : A finite element model
- 2018
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In: International Journal of Structural Engineering. - Olney : InderScience Publishers. - 1758-7328 .- 1758-7336. ; 9:4, s. 273-288
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Journal article (peer-reviewed)abstract
- Skew slabs enable to achieve a variety of solutions in, for instance, roadway alignments which contribute to a minor environmental impact for new road construction projects. But the force flow in skew slabs is much more complicated than in straight slab. Thus, the problem is more critical when constructing skew slabs. The complex behaviour of skew bridge slabs makes the utilisation of finite element method (FEM) the most critical and essential analytical tool to model reinforced concrete skew slab and calculate the non-linear behaviour of its structural members with considerable accuracy. This paper uses the general purpose of 3D finite element and ABAQUS software to design straight and skew slabs. Six separate bridge slab models/sketches of different angles were produced. Same material and material properties, loading, boundary conditions and meshing were used to determine the response and behaviour of each bridge slab. The slab is made of concrete class C35/45.
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| 4. |
- Tang, Luping, 1956, et al.
(author)
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Validation of models for prediction of chloride ingress in concrete exposed in de-icing salt road environment
- 2013
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In: International Journal of Structural Engineering. - 1758-7328 .- 1758-7336. ; 4:1-2, s. 86-99
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Journal article (peer-reviewed)abstract
- This paper presents the results from validation of models for prediction of chloride ingress in concrete exposed in de-icing salt road environment. Three models including the simple error-function complement (ERFC) model, the DuraCrete model and the ClinConc model, were evaluated using the measurement data collected from both the field exposure site after over ten years exposure and the real road bridges after 25-30 years in service. The sensitivity of input parameters in each model is analysed. The results show that, among different input parameters, the age factor is the most sensitive one. The simple ERFC model significantly overestimates chloride ingress. The DuraCrete model, if the input parameters are properly selected, may give a reasonably good prediction, otherwise often underestimates chloride ingress. The ClinConc model in general gives fairly good predictions for chloride ingress in de-icing salt road environment with heavy traffic at high speed.
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| 5. |
- Abbasiverki, Roghayeh, et al.
(author)
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Seismic response of large diameter buried concrete pipelines subjected to high frequency earthquake excitations
- 2020
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In: Int. J. Structural Engineering. - 1758-7328. ; 10:4, s. 307-329
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Journal article (peer-reviewed)abstract
- Buried pipelines are tubular structures that cross large areas with different geological conditions. During an earthquake, imposed loads from soil deformations on pipelines may cause drastic damages. In this study two dimensional finite element models of pipelines and surrounding soils are usedfor simulation of seismic waves that propagate from the bedrock through thesoil. The models describe both longitudinal and transverse cross-sections ofpipelines and the soil-pipe interaction is described as a nonlinear behaviour.The effects of uniform ground with different burial depth and soil layer thickness, soil stiffness and non-uniform ground on the seismic response of reinforced concrete pipelines is studied. Two earthquakes, with high and low frequency contents, are employed for the dynamic analysis. The results show asignificant effect on the response due to non-uniform ground caused by inclined bedrock, especially for high frequency earthquake excitations.
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