Influência da distribuição de espaçadores no cobrimento e na vida útil de lajes maciças

Palm, Vinícius; Maran, Ana Paula; Barreto, Maria Fernanda Fávero Menna; Molin, Denise Carpena Coitinho Dal; Masuero, João Ricardo

doi:10.1590/s1678-86212020000300452

Cited by 3 publications

(6 citation statements)

References 10 publications

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“…The simulation was carried out by the Displacement Method. The slabs were chosen because they are one of the hardest elements to obtain the intended design concrete cover [30] and due to their solid characteristic they are evaluated in a number of studies [30], [32], [34]- [37]. To perform this work, the slabs with 200 x 200 cm dimensions were cast with a reinforcement mesh spacing of 20 cm.…”

Section: Computational Simulationmentioning

confidence: 99%

“…This diameter is not typically used in solid slabs, however it was considered in this laboratory investigation because it is allowed by the standard [12]. The other diameters are frequently used in solid slabs [27], [34], [37]- [39] and were chosen for verification in structural design.…”

Section: Computational Simulationmentioning

confidence: 99%

“…Many researchers report the failure to obtain the cover thickness specified in the current reinforced concrete structure constructions [27], [30], [31], [33], [34], where the probability of inefficient cover varies between 38.7% and 88.8% in solid slabs [30]. In general, the design reinforcement position is not achieved even before construction [35].…”

Section: Introductionmentioning

confidence: 99%

“…Among the structural elements, the slabs are one of the most damaged elements as a result of insufficient cover thickness [27]. Unsatisfactory covers could be a consequence of uneven placement or insufficient quantity of spacers, lack of formwork leveling [35], [36], spacers with a poor performance [11], wrong choice of spacers, or workers walking through the reinforcement meshes [34]. Furthermore, the minimum cover execution tolerance value of 5 mm, which is related to a good execution quality control, are not met, being directly related to the reduction of building durability [32], [34].…”

Section: Introductionmentioning

confidence: 99%

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Computational and experimental simulation to analyze loss in concrete cover by reinforcement deformation in solid slabs

Maran

Barreto

Molin

et al. 2022

Rev. IBRACON Estrut. Mater.

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Adequate cover thickness contributes to the correct performance of reinforced concrete structures. Spacers are recommended in standards to maintain a concrete cover; however, many regulations do not provide sufficient guidelines for their use, resulting in poor construction. A research program was developed for solid slabs through computational and experimental simulations to minimize errors in the cover by assessing different reinforcement bar diameters and spacer distribution, considering realistic element construction and standards, combining theory with practice. The results show that the use of spacers does not guarantee the design cover for some reinforcement bar diameters, as 4.2 and 5.0 mm, and regardless of the spacer distribution configuration assessed, these meshes undergo permanent deformation, thereby damaging the cover and consequently impact structural performance. Meshes of 6.3 and 8.0 mm diameters present deformation within the cover tolerance. Therefore, it is preferable to choose bigger diameters and larger mesh spacing to guarantee the projected cover, contributing to the correct performance of the structures, solving one of the major problems in this type of construction.

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Section: Computational Simulationmentioning

confidence: 99%

Section: Computational Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Computational and experimental simulation to analyze loss in concrete cover by reinforcement deformation in solid slabs

Maran

Barreto

Molin

et al. 2022

Rev. IBRACON Estrut. Mater.

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“…Para as estruturas em concreto armado, a proteção das armaduras é um dos principais fatores para atingir o desempenho e durabilidade de projeto, e isso só é possível quando se tem qualidade do concreto e da espessura do cobrimento (PALM et al, 2020).…”

Section: Introductionunclassified

Estudo De Caso Sobre a Importância Das Normas Na Durabilidade Das Estruturas De Concreto Armado E a Inspeção Predial Como Ferramenta De Controle

Giannakos¹,

Mendes²,

Lenz³

et al. 2022

Congresso Brasileiro De Patologia Das Construções

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Os projetos de estruturas de concreto armado devem seguir as normas técnicas existentes, de forma a garantir a durabilidade mínima das edificações, afim de evitar o surgimento de manifestações patológicas. A inspeção predial acaba sendo ferramenta importante para identificar estas anomalias, diagnosticar e propor a terapia adequada da estrutura danificada. O presente estudo tem como objetivo relacionar a falta de cobrimento com o envelhecimento precoce da estrutura, bem como as diferenças e evolução da NBR 6118 (ABNT, 1980) nos principais fatores para durabilidade estabelecidos pela norma em vigor. Na edificação vistoriada, foi constatado cobrimento inferior ao mínimo constante na norma. O não atendimento dos parâmetros de durabilidade estabelecidos em norma, tal como o cobrimento mínimo, afetam diretamente a vida útil da estrutura e acabam facilitando o surgimento de manifestações patológicas. Palavras-chave: corrosão de armadura; inspeção predial; cobrimento de armadura.

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A Monte Carlo-Based Approach to Assess the Reinforcement Depassivation Probability of RC Structures: Simulation and Analysis

et al. 2023

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In this work, an approach is presented to assess the reinforcement depassivation probability of reinforced concrete structures under corrosion induced by carbonation or chloride diffusion. The model consists of coupling mathematical formulations of CO2 and Cl− diffusion with Monte Carlo simulation (MCS). Random events were generated using MCS to create several design life and environmental scenarios. A case study was performed by simulating five Brazilian environmental conditions and distinct mixes of concrete. The effect of input parameters on the reinforcement concrete depassivation probability was evaluated. The results point out that the depassivation probability due to carbonation is more significant in urban centers, and the compressive strength of concrete has the main influence on the depassivation probability. Results also showed that the depassivation probability due to chloride ingress is influenced by, in order of importance, the chloride content on the surface (61.4%), concrete cover (20.3%), compressive strength (7.1%), relative humidity (6.1%), and temperature (5.1%). In addition, an increase in the compressive strength of concrete, from 30 to 50 MPa, can reduce depassivation probability by up to 70%, resulting in a concrete structure that attends the durability limit state. Thus, by incorporating probabilistic approaches, this model can be a valuable tool in the civil construction industry for studying the improvement of durability, reliability, and safety of reinforced concrete structures.

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Influência da distribuição de espaçadores no cobrimento e na vida útil de lajes maciças

Cited by 3 publications

References 10 publications

Computational and experimental simulation to analyze loss in concrete cover by reinforcement deformation in solid slabs

Computational and experimental simulation to analyze loss in concrete cover by reinforcement deformation in solid slabs

Estudo De Caso Sobre a Importância Das Normas Na Durabilidade Das Estruturas De Concreto Armado E a Inspeção Predial Como Ferramenta De Controle

A Monte Carlo-Based Approach to Assess the Reinforcement Depassivation Probability of RC Structures: Simulation and Analysis

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