scholarly journals Probabilistic Evaluation of Service Life for Reinforced Concrete Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sanjeev Kumar Verma ◽  
Sudhir Singh Bhadauria ◽  
Saleem Akhtar

Degradation of performance and deterioration of different components of reinforced concrete (RC) structures increase with the age of structure. This deterioration of reinforced component depends on several parameters. However, modeling service life of RC structure by considering all the parameters is a difficult job, as most of the parameters are uncertain in nature. Probabilistic models account well for the uncertainties in the parameters responsible for deterioration of RC structures. This paper presents a review of several recent service life models developed using probability based concepts.

2018 ◽  
Vol 1 (1) ◽  
pp. 702-708
Author(s):  
Onur Onat ◽  
Burak Yön

Failure mode of reinforced concrete (RC) structures are classified according to tension reinforcement ratio of beam elements. To determine effect of tension reinforcement ratio on performance of RC structure, two planar RC structure were selected. One of them is 5 stories other of them is 7 stories. Two different concrete class, C20 and C25, were considered for analysis. Three tension reinforcement combinations were considered, three different tension reinforcement ratios were used. First case is the ratio of the tension reinforcement is lower than that of the compression reinforcement, second case is the ratio of the tension reinforcement is equal to the ratio of the compression reinforcement and third case is the ratio of the tensile reinforcement is higher than the compression reinforcement.


2021 ◽  
Author(s):  
Sergey Leonovich ◽  
Evgeniy Shalyy ◽  
Elena Polonina ◽  
Elena Sadovskaya ◽  
Lev Kim ◽  
...  

Section I of the monograph is devoted to an urgent problem - forecasting the durability of port reinforced concrete structures, the destruction of which is associated with corrosion of steel reinforcement caused by chloride aggression and carbonation of concrete. The analysis of models for calculating the service life of structures and experimental data is carried out, the life cycles for the main degradation processes in concrete and reinforcement, the periods of initiation and propagation of corrosion are considered, the influence of environmental factors (temperature, humidity) and the quality of concrete (In/C, cement consumption, diffusion coefficient) on the kinetics of chloride penetration and the movement of the carbonation front is taken into account. Probabilistic models of basic variables are considered, the limiting states of port reinforced concrete structures for the durability of reinforced concrete structures based on the reliability coefficient for service life are formulated. Sections II and III describe modern methods of restoration and restoration of reinforced concrete port structures subjected to corrosion destruction using nanofibrobeton. The concept of multilevel reinforcement has been implemented. Methods of experimental fracture mechanics were used to evaluate the joint work of exploited concrete and reinforcement nanofibre concrete. It is intended for scientific and engineering staff of universities, research and design organizations.


2020 ◽  
Vol 868 ◽  
pp. 3-9
Author(s):  
Jan Mlčoch ◽  
Miroslav Sýkora

The construction industry is now facing expanding and extensive activities in the area of assessing and retrofitting buildings and bridges that aligns with the sustainable construction strategy. These activities recognise the importance of extending the life of existing construction works thereby delivering environmental, economic and socio-political benefits. Reinforced concrete structures and their reliability are currently receiving considerable attention as a significant part of these structures reaches the design service life. Degradation processes such as carbonation- and chloride-induced corrosion have a major influence on the reliability and serviceability of concrete structures. The submitted study is primarily focused on reinforced concrete structures whose main degradation factor is carbonation of the concrete cover. Examples of such structures are cooling towers or industrial chimneys. Structures in the power industry are usually designed for service life of 40 years. Carbonation-induced corrosion results in visible cracks and unacceptable spalling of concrete cover. The aim of the study is to improve predictions of carbonation-induced corrosion propagation and to critically compare the criteria for degradation level assessment used in practice. The probabilistic analysis is based on measurements of concrete cover and carbonation depths and continuous observations of signs of corrosion on structural surfaces. The example of an industrial chimney shows that the limit of a severe failure, which requires (possibly repeated) minor repairs, is exceeded after about 17 years. The critical failure limit (30% of structural surface with visible signs of corrosion) is reached after 50 years, which seems to be sufficient as it is after 10 years than the usual design service life.


2015 ◽  
Vol 1111 ◽  
pp. 187-192
Author(s):  
Corina Sosdean ◽  
Liviu Marsavina ◽  
Geert de Schutter

Reinforced concrete (RC) became one of the most widely used modern building materials. In the last decades a great interest has been shown in studying reinforcement corrosion as it became one of the main factors of degradation and loss of structural integrity of RC structures. The degradation process is accelerated in the case of RC structures situated in aggressive environments like marine environments or subjected to de-icing salts. In this paper it is shown how steel corrosion of the embedded rebars occurs and how this affects the service life of reinforced concrete structures. Also, an experimental study regarding the combined effect of carbonation and chloride ingress was realized. Samples with and without rebars were drilled from a RC slab which was stored in the laboratory for two years. Non-steady state migration tests were realized in order to determine the chloride profile, while the carbonation depth was measured using the colorimetric method based on phenolphthalein spraying. It was concluded that carbonation has a significant effect on chloride ingress, increasing it.


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