Otimização de estruturas reticuladas em concreto armado considerando incertezas e riscos

Ribeiro, Lucas da Rosa

doi:10.11606/d.18.2020.tde-24042020-173718

Cited by 8 publications

(9 citation statements)

References 24 publications

(32 reference statements)

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“…Calcium carbonate does not cause concrete deterioration. However, its formation is characterized by the reduction of alkalinity due to the decrease in the concentration of hydroxyls in the interstitial solution, leading to a reduction in the pH to values close to 8 (Ribeiro et al, 2018). The Pourbaix diagram (Figure 4) presents the immunity, passivation and corrosion situations for steel in an iron-water system at 25 °C (without chlorides).…”

Section: Introductionmentioning

confidence: 99%

Functionally graded concrete: porosity gradation to enhance durability under carbonation

Ribeiro,

Silva,

Dias

2024

Ambient. constr.

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The present paper evaluated the potential application of the functionally graded material (FGM) concept to develop more durable concrete to carbonation, one of the main degradation mechanisms of reinforced concrete structures. Accelerated carbonation tests with controlled temperature (27 ( 2°C), CO2 concentration (3 ( 0.5%) and humidity (65 ( 5%) were carried out in homogeneous concretes and with functional gradation in which the porosity of the material was varied across the slices. For the manufacture of graded concrete specimens, concretes with water/cement ratios equal to 0.35, 0.45, and 0.55 were produced, with lower porosity (w/c = 0.35) close to the surface of the specimen. The advance of the carbonation front was evaluated after 8, 9, 10, 14, and 24 weeks of accelerated exposure, using the chemical indicator phenolphthalein. The results show that the functionally graded concrete had a carbonation coefficient (K) slightly higher than that of the concrete with a w/c ratio equal to 0.35 (1.71 and 1.54 mm.week-0.5, respectively) and much lower than concrete with water-cement ratio equal to 0.45 (2.31 mm.week-0.5) and 0.55 (3.78 mm.week-0.5). This demonstrates that functional grading can be an efficient method to increase the durability of concrete elements subject to carbonation.

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Section: Introductionmentioning

confidence: 99%

Functionally graded concrete: porosity gradation to enhance durability under carbonation

Ribeiro,

Silva,

Dias

2024

Ambient. constr.

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“…According to El-Reedy [2], this type of pathological manifestation costs billions of dollars around the world. A worrying factor, according to Cascudo [3] and Ribeiro [4], a good part of the buildings in the major Brazilian urban center and its infrastructure were built in the '70s and '80s, reaching, nowadays, approximately between 40 to 50 years of age, respectively. Structures built at that time are, thus, reaching a point in which repairs and maintenance become routine, therefore, the problems related to reinforcement corrosion tend to accentuate in the coming years.…”

Section: Introductionmentioning

confidence: 99%

Corrosion in reinforced concrete: Diagnostics through Potential Corrosion Technique

Reginato

Lorenzi

Oliveira

et al. 2023

Preprint

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Among the processes that accelerate the loss of performance of reinforced concrete structures, considering their frequent occurrence and severity, corrosion of reinforcement can be seen as one of the most important. A worrying factor is that most buildings in the main Brazilian urban centers are between 40 and 50 years old, a time when repairs and maintenance become more routine. Therefore, the problems related to the corrosion of the reinforcements tend to accentuate in the coming years and the identification of corrosion will play an important role. Thus, this research has the purpose of analyzing the application of the diagnosis through potential corrosion techniques. For this, full-scale reinforced concrete beams were analyzed. Corrosion was stimulated by the Modified Immersion Accelerated Corrosion - CAIM method, at three levels of mass loss: 5%, 10%, and 15%. The diagnostic technique through the corrosion potential was applied, in which it was observed that there is uncertainty in the corrosion evaluation for the mass loss levels of 5 and 10%, resulting in a corrosion uncertainty interval, but at 15%, the potential technique proved to be satisfactory.

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“…Even being constituted by elements composed of concrete and steel, so that they can act together in the load bearing process of a building, there are many problems that can affect this structure, characterized as simple or complex pathologies, compromising the integrity of the building (RIBEIRO et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Recent studies on the use of simulated concrete pore solution for corrosion evaluation: a systematic review using prisma

D'Oliveira,

Sidel,

Guarda

et al. 2023

OLEL

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The use of simulated concrete pore solutions (SCP) is a viable alternative for studying the behavior of the steel/concrete interface, mainly due to the possibility of reproducibility in the laboratory. However, this solution needs to represent the reality of what happens in the concrete pores, regarding the ions present in the solution and a stable pH, close to 12.5. Therefore, this article presents a systematic review of the use of SCP in the assessment of adherence since 2018. The investigation followed the PRISMA protocol. After including/excluding steps, 58 studies were included in the review. After the evaluation of these studies, the results were presented focusing on the types of SCP, the experiments carried out and the resistance monitoring methods that used electrochemical experiments, spectroscopy and image analysis. In short, this methodology makes it possible to identify the main knowledge gaps in this area.

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Otimização de estruturas reticuladas em concreto armado considerando incertezas e riscos

Cited by 8 publications

References 24 publications

Functionally graded concrete: porosity gradation to enhance durability under carbonation

Functionally graded concrete: porosity gradation to enhance durability under carbonation

Corrosion in reinforced concrete: Diagnostics through Potential Corrosion Technique

Recent studies on the use of simulated concrete pore solution for corrosion evaluation: a systematic review using prisma

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