Service life modelling The application of simple modeling techniques to corrosion induced deterioration of reinforced concrete

As part of a marine habitat enhancement project, the physical and chemical deterioration of reinforced concrete reefs that were fully immersed in Tongyeong waters of Korea was investigated. For the investigation, marine environmental factors such as seawater, salinity, pH, dissolved oxygen, sea-bottom materials, and water depth of the targeted sites were surveyed from 1997 to 2001. Then, four reinforced concrete reefs from four different sites were recovered and tested by using various destructive and nondestructive methods. Based on the observations and test results, it was seen that the reinforced concrete reefs have sound physical and chemical properties, except for chloride concentration and its associated factors. However, because of the lack of dissolved oxygen in the targeted seawaters and its continuous supply, it is concluded that the originally designed service life will be achieved, and in fact the concrete reefs will have an even longer service life than expected. By considering an extreme event such as impact loading under installation and construction, a new minimum concrete cover depth of 40 mm is introduced into practice.

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Influence of an Applied Compressive Stress on Service Life of Reinforced Concrete Structures in Marine Environment

Restoration of Buildings and Monuments ◽

10.1515/rbm-2013-6569 ◽

2013 ◽

Vol 19 (1) ◽

pp. 3-10

Author(s):

F.H. Wittmann ◽

F. Jiang ◽

T. Zhao ◽

Y. Wang

Keyword(s):

Reinforced Concrete ◽

Service Life ◽

Compressive Stress ◽

Marine Environment ◽

Concrete Structures ◽

Reinforced Concrete Structures

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Specific feature of the restoration of operability of KPP-5 fasteners by using PRP-3.2 and PRP-3.2.1 rail pads

MATEC Web of Conferences ◽

10.1051/matecconf/201823001005 ◽

2018 ◽

Vol 230 ◽

pp. 01005

Author(s):

Denis Fast ◽

Natalia Bugaets ◽

Volodymir Vitolberg ◽

Alexandr Lichodey ◽

Volodymyr Stefanov

Keyword(s):

Reinforced Concrete ◽

Service Life ◽

Traffic Load ◽

Rational Use ◽

Pressing Force ◽

Standard Service

Areas of rational use of the track construction with reinforced concrete sleepers have been defined, however, it requires improving and the problem of intermediate rail fastenings is particularly serious here. The most common intermediate rail fasteners used in Ukrzaliznytsya are lining terminal-bolted fasteners of KB type and direct fixation boltless fastening type KPP-5. Calculations have been made for the restoration of operability of KPP-5 fasteners using PRP-3.2 repair pads with a thickness of 9 mm and PRP-3.2.1 with a thickness of 10 mm. It has been established that in the sections with the traffic load of more than 15 million ton km/km in year, restoration works should be performed after 13 years of operation. Using 10 mm thick PRP-3.2.1 rail pads will provide the necessary pressing force of the rail base against the sleeper until the expiration of the standard service life – no more than 30 years. When the traffic load is less than or equal to 15 million ton km/km in year, recovery can be performed after 22 years of operation. The use of both types of pads will ensure the reliable functioning of KPP-5 fasteners until the expiration of its service life.

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