On-site investigations on concrete resistivity – a parameter of durability calculation of reinforced concrete structures

2006 ◽  
Vol 57 (12) ◽  
pp. 932-939 ◽  
Author(s):  
M. Büteführ ◽  
C. Fischer ◽  
C. Gehlen ◽  
K. Menzel ◽  
U. Nürnberger
1997 ◽  
Vol 3 (6) ◽  
pp. 581-602
Author(s):  
H. Wojtas

Abstract In this state of the art report the electrochemical, non destructive techniques for the survey, assessment and the quality control of reinforced concrete structures such as the potential mapping, the measuring of concrete resistivity and the polarisation resistance for on-site applications are described. Along with a short description of each technique especially those aspects are discussed, that are important for on-site applications: possibilities and limits of the technique as well its suitability for use in the different stages of rehabilitation works. The examples from practical on-site applications will be presented in a following report.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Lukasz Sadowski

In recent years, the corrosion of steel reinforcement has become a major problem in the construction industry. Therefore, much attention has been given to developing methods of predicting the service life of reinforced concrete structures. The progress of corrosion cannot be visually assessed until a crack or a delamination appears. The corrosion process can be tracked using several electrochemical techniques. Most commonly the half-cell potential measurement technique is used for this purpose. However, it is generally accepted that it should be supplemented with other techniques. Hence, a methodology for assessing the probability of corrosion in concrete slabs by means of a combination of two methods, that is, the half-cell potential method and the concrete resistivity method, is proposed. An assessment of the probability of corrosion in reinforced concrete structures carried out using the proposed methodology is presented. 200 mm thick 750 mm  ×  750 mm reinforced concrete slab specimens were investigated. PotentialEcorrand concrete resistivityρin each point of the applied grid were measured. The experimental results indicate that the proposed methodology can be successfully used to assess the probability of corrosion in concrete structures.


Currently, prefabricated reinforced concrete structures are widely used for the construction of buildings of various functional purposes. In this regard, has been developed SP 356.1325800.2017 "Frame Reinforced Concrete Prefabricated Structures of Multi-Storey Buildings. Design Rules", which establishes requirements for the calculation and design of precast reinforced concrete structures of frame buildings of heavy, fine-grained and lightweight structural concrete for buildings with a height of not more than 75 m. The structure of the set of rules consists of eight sections and one annex. The document reviewed covers the design of multi-story framed beam structural systems, the elements of which are connected in a spatial system with rigid (partially compliant) or hinged joints and concreting of the joints between the surfaces of the abutting precast elements. The classification of structural schemes of building frames, which according to the method of accommodation of horizontal loads are divided into bracing, rigid frame bracing and framework, is presented. The list of structural elements, such as foundations, columns, crossbars, ribbed and hollow floor slabs and coatings, stiffness elements and external enclosing structures is given; detailed instructions for their design are provided. The scope of the developed set of rules includes all natural and climatic zones of the Russian Federation, except seismic areas with 7 or more points, as well as permafrost zones.


Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.


2019 ◽  
Vol 9 (1) ◽  
pp. 61
Author(s):  
SINGH RAVIKANT ◽  
KUMAR SINGH VINAY ◽  
YADAV MAHESH ◽  
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2014 ◽  
Vol 4 (3) ◽  
pp. 1-9
Author(s):  
Badrinarayan Rath ◽  
◽  
Shirish Deo ◽  
Gangadhar Ramtekkar ◽  
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...  

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