Carbono incorporado devido a modificações estruturais em lajes compósitas de aço e concreto para reduzir vibrações excessivas geradas por cargas dinâmicas de caminhada

Samuel Honório Silva Araújo , João Pedro da Silva Sousa , Márcio Santos Gonçalves

Resumo
Lajes compósitas de aço e concreto estão progressivamente mais susceptíveis a vibrações verticais induzidas por cargas de caminhada. Geralmente, modificações estruturais são realizadas nessas lajes (ex.: aumento da espessura da camada de concreto e alterações nas dimensões de vigas metálicas) para reduzir tais vibrações, conferindo maior massa e rigidez estrutural. Entretanto, esta prática tem frequentemente resultado em: 1) maiores taxas de carbono incorporado na estrutura; 2) maior consumo de concreto e de aço; e 3) maior custo da edificação. As primeiras duas consequências são especialmente preocupantes devido ao atual cenário de emergência climática global. Neste contexto, o uso de atuadores dinâmicos mostra-se promissor na redução destas vibrações com menores impactos ambientais. Este artigo compara impactos ambientais gerados por modificações estruturais e por atuadores dinâmicos num modelo computacional de laje. Resultados mostraram que modificações estruturais geraram laje 95% mais pesada e com carbono incorporado 33% maior que o uso de atuadores.

Palavras-chave
Lajes; Vibrações; Carbono incorporado; Atuadores dinâmicos.

Abstract
Embodied carbon due to structural modifications in steel and concrete composite slabs to reduce excessive vibrations generated by dynamic walking loads. Composite steel-concrete slabs are becoming increasingly susceptible to vertical vibrations induced by walking loads. Typically, structural modifications are implemented in these slabs (e.g., increasing the thickness of the concrete layer or altering the dimensions of steel beams) to reduce such vibrations by increasing the overall mass and stiffness of the structure. However, this practice has often resulted in: (1) higher embodied carbon rates in the structure; (2) greater consumption of concrete and steel; and (3) increased building costs. The first two consequences are particularly concerning given the current global climate emergency. In this context, the use of dynamic actuators has shown promise in mitigating these vibrations with lower environmental impacts. This paper compares the environmental impacts generated by structural modifications and by dynamic actuators in a computational slab model. Results showed that structural modifications produced a slab that was 95% heavier and had 33% higher embodied carbon than when using actuators.

Keywords
Slabs; Vibrations; Embedded carbon; Dynamic actuators.

DOI
10.21438/rbgas(2025)123132


Texto completo

 Baixar este arquivo PDF

 


Referências
Chen, S; Zhang, R.; Zhang, J. Human-induced vibration of steel-concrete composite floors. Proceedings of the Institution of Civil Engineers - Structures and Buildings, v. 171, n. 1, p. 50-63, 2018. https://doi.org/10.1680/jstbu.16.00179

EN - European Commission. Proposal for a regulation of the European Parliament and of the Council establishing the framework for achieving climate neutrality and amending Regulation (EU) 2018/1999 (European Climate Law). Belgium: EN, 2017.

Hanagan, L. M. Walking-induced floor vibration case studies. Journal of Architectural Engineering, v. 11, n. 1, p. 14-18, 2005. https://doi.org/10.1061/(ASCE)1076-0431(2005)11:1(14)

Hanagan, L. M.; Chattoraj, M. C. A whole building cost perspective to floor vibration serviceability. Proceedings of the 2006 Architectural Engineering Conference, Omaha, 2006. https://doi.org/10.1061/40798(190)37

Hanagan, L.; Murray, T. Active control of floor vibration: Implementation case studies. Proceedings of the 1995 American Control Conference, 1995. https://doi.org/10.1109/ACC.1995.531220

ISO - International Organization for Standardization. ISO 2631-2: Mechanical vibration and shock - Evaluation of human exposure to whole-body vibration - Part 2: Human exposure to continuous and shock-induced vibration in buildings (1 Hz to 80 Hz). Geneva: ISO, 2003.

ISO - International Organization for Standardization. ISO 10137: Bases for design of structures – Service ability of buildings and walkways against vibrations. Geneva: ISO, 2007.

Muhammad, Z.; Reynolds, P.; Avci, O.; Hussein, M. Review of pedestrian load models for vibration serviceability assessment of floor structures. Vibration, v. 2, n. 1, p. 1-24, 2019. https://doi.org/10.3390/vibration2010001

Petrovic, S.; Pavic, A. Effects of non-structural partitions on vibration performance of floor structures: A literature review. Proceedings of the 8th International Conference on Structural Dynamics, EURODYN, 2011.

Poole, I; Gabbianelli, M.; Arnold, W.; Orr, J. Seeing the bigger picture: Industry emissions, your project and the performance gap. The Structural Engineer, v. 99, n. 10, p. 1-4, 2021. https://doi.org/10.56330/YZRQ9810

Saidi, I.; Haritos, N.; Gad, E. F.; Wilson, J. L. Floor vibrations due to human excitation: Damping perspective. Camberra: Swinburne University of Technology, Conference Contribution, 2006. https://doi.org/10.25916/sut.26285590.v1

Sartori, T. A. B. Análise comparativa de custos para a execução de uma laje steel deck. Porto Alegre: Pontifícia Universidade Católica do Rio Grande do Sul, 2012. (Trabalho de conclusão de curso).

Smith, A. L.; Hicks, S. J.; Devine, P. J. Design of floors for vibration: A new approach (Revised Edition, February 2009). Ascot: The Steel Construction Institute, 2009.

Willford, M.; Young, P. A design guide for footfall induced vibrations of structures: A tool for designers to engineer the footfall vibration characteristics of buildings or bridges. Camberley: The Concrete Center, 2006.


 

ISSN 2359-1412