scholarly journals Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures

10.3791/56229 ◽  
2017 ◽  
Author(s):  
Ueli M. Angst ◽  
Carolina Boschmann ◽  
Matthias Wagner ◽  
Bernhard Elsener
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Threshold Value ◽  
Reinforced Concrete Structures ◽  
Experimental Protocol ◽  
Chloride Threshold

scholarly journals Chloride Levels That Initiated Corrosion of Duplex Stainless Steel Embedded in Mortar

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Yu-You Wu ◽  
Francisco Presuel-Moreno
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Electrochemical Impedance ◽  
Concrete Structures ◽  
Chloride Concentration ◽  
Threshold Value ◽  
Open Circuit ◽  
Reinforced Concrete Structures ◽  
Premature Failure ◽  
Chloride Threshold

Chloride-induced corrosion of carbon steel has been widely recognized as one of the main causes of premature failure on the reinforced concrete structures. Various strategies and measures such as employing stainless steel reinforcements have been developed to address this problem. Past studies have been concerned with the identification and characterization of chloride threshold since corrosion would not initiate as long as the chloride concentration values at the reinforcing stainless steel depth remains below this threshold value. It is therefore a critical parameter for the design of new stainless steel reinforced concrete structures and the assessment of existing concrete structures. This study presents the finding on the chloride threshold of stainless steel UNS32304 embedded in mortar with two different mixes. Reinforced mortar specimens were subjected to ponding exposure and wet/dry cycle exposure with a sodium chloride solution. The specimens were monitored by using the measurements of the open circuit potential, electrochemical impedance spectroscopy, and linear polarization resistance. The paper also discusses the chloride threshold values of such stainless steel embedded in mortar and concrete with other mixes reported by other researchers and the factors that may affect these values.

Design of precast reinforced concrete structures of frame buildings: a new set of rules

2019 ◽  
pp. 4-9 ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Building Frames ◽  
Fine Grained ◽  
Rigid Frame ◽  
Floor Slabs ◽  
Frame Buildings ◽  
Spatial System ◽  
Precast Elements

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.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

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.

SEISMIC ANALYSIS OF MULTISTOREY REINFORCED CONCRETE STRUCTURES

2019 ◽  
Vol 9 (1) ◽  
pp. 61
Author(s):  
SINGH RAVIKANT ◽  
KUMAR SINGH VINAY ◽  
YADAV MAHESH ◽  
◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Concrete Structures ◽  
Reinforced Concrete Structures

Reducing The Life Cycle Cost of Reinforced Concrete Structures by using Fiber in Concrete

2014 ◽  
Vol 4 (3) ◽  
pp. 1-9
Author(s):  
Badrinarayan Rath ◽  
◽  
Shirish Deo ◽  
Gangadhar Ramtekkar ◽  
◽  
...  
Keyword(s):  
Life Cycle ◽  
Reinforced Concrete ◽  
Life Cycle Cost ◽  
Concrete Structures ◽  
Reinforced Concrete Structures
Sign in / Sign up

Export Citation Format

Share Document