SIMULAÇAÕ NUMÉRICA MEDIANTE PROBLEMA INVERSO DO COMPORTAMENTO TERMOMECÂNICO DO CONCRETO DURANTE PROCESSO DE HIDRATAÇÃO

SIMULAÇAÕ NUMÉRICA MEDIANTE PROBLEMA INVERSO DO COMPORTAMENTO TERMOMECÂNICO DO CONCRETO DURANTE PROCESSO DE HIDRATAÇÃO

Quintana, Osvaldo D.; Aquino, Antonio; López, Rubén; Campello, Jean Marie Désir Eduardo M. B.

Full Article:

Lately there has been a development of various computational models for studying the thermo mechanical behavior of concrete, where the input data, in general, are obtained from the literature. However, the concrete properties vary according to the used components. The purpose of this study is to estimate the heat generation and thermal properties due to chemical reaction in concrete of different strengths. To obtain the thermal parameters and analyzing the results we used an inverse algorithm combined with FEM. The binder used was composite cement produced locally. The experimental program comprised in the use of thermocouples located within the test bodies seventy-five cubic centimeters sides under semi-adiabatic conditions, they were recorded temperature values generated during the hydration process in a period of twenty-eight days with a time interval of one hour. These parameters were used lately for the analysis of samples. The main objective is to provide a numerical method consisting in the use of an inverse algorithm to estimate the thermal parameters associated with the generation of heat, specific heat and thermal conductivity to use for solving the direct heat transfer problems. This methodology allows the study of thermal and mechanical behavior of concrete at early-ages. Parameters were obtained during the hydration process, performing numerical simulations with those data. The results show a good approximation to the experimental data. It is concluded from this study that this proposed method is an accurate, stable, and efficient method for the analysis of early-ages behavior of concrete structures.

Lately there has been a development of various computational models for studying the thermo mechanical behavior of concrete, where the input data, in general, are obtained from the literature. However, the concrete properties vary according to the used components. The purpose of this study is to estimate the heat generation and thermal properties due to chemical reaction in concrete of different strengths. To obtain the thermal parameters and analyzing the results we used an inverse algorithm combined with FEM. The binder used was composite cement produced locally. The experimental program comprised in the use of thermocouples located within the test bodies seventy-five cubic centimeters sides under semi-adiabatic conditions, they were recorded temperature values generated during the hydration process in a period of twenty-eight days with a time interval of one hour. These parameters were used lately for the analysis of samples. The main objective is to provide a numerical method consisting in the use of an inverse algorithm to estimate the thermal parameters associated with the generation of heat, specific heat and thermal conductivity to use for solving the direct heat transfer problems. This methodology allows the study of thermal and mechanical behavior of concrete at early-ages. Parameters were obtained during the hydration process, performing numerical simulations with those data. The results show a good approximation to the experimental data. It is concluded from this study that this proposed method is an accurate, stable, and efficient method for the analysis of early-ages behavior of concrete structures.

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DOI: 10.5151/meceng-wccm2012-19362

Referências bibliográficas

• [1] American Concrete Institute Committe 116 (2000), “116R-2000: Cement and Concrete Terminology”, Technical Documents, ACI Manual of Concrete Practice, Farmington Hills, Michigan.
• [2] American Concrete Institute Committe 207 (2002), “Mass Concrete”, ACI Manual of Concrete Practice.
• [3] American Concrete Institute Committe 207 (2002), “Effect of Restraint, Volume Change and Reinforcement on Cracking of Mass Concrete”, ACI Manual of Concrete Practice.
• [4] Coussy, Olivier. (2.004) Poromechanics. John Wiley Andamp; Sons Ltd. England.
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• [6] Neville, A. M., (1999). “Properties of Concrete” Pearson Education Limited, London.
• [7] Nambiar, O. N. N. , Krishnamurthy, V., (1984). “Control of Temperature in Mass Concrete Pours”. In: Indian Concrete Journal, volume 58, N° 3. P: 67-73
• [8] Özisik, Orlande. (2000) Inverse Heat Transfer. Taylor Andamp; Francis. USA.
• [9] P. Kumar Metha and Paulo J.M. Monteiro (2008) Concreto, Microestrutura, Propiedades e Materiais. Ibracon, São Paulo, SP, Brasil.
• [10] Ulm, F.-J., Coussy, O. (1995). Modelling of Thermochemomechanical Couplings of Concrete at Early Ages. Journal of Engineering Mechanics (ASCE), 121(7): 785 – 794.
• [11] Rilem Report 15. (1998). Prevention of Thermal Cracking In Concrete At Early Ages. E Andamp; FN Spon. London.

Como citar:

Quintana, Osvaldo D.; Aquino, Antonio; López, Rubén; Campello, Jean Marie Désir Eduardo M. B.; "SIMULAÇAÕ NUMÉRICA MEDIANTE PROBLEMA INVERSO DO COMPORTAMENTO TERMOMECÂNICO DO CONCRETO DURANTE PROCESSO DE HIDRATAÇÃO", p-3380-3395. In: In Proceedings of the 10th World Congress on Computational Mechanics [= Blucher Mechanical Engineering Proceedings, v. 1, n. 1]. São Paulo: Blucher, 2014.
ISSN 23580828, DOI 10.5151/meceng-wccm2012-19362