Evaluation of the homogenization degree of the ready-mixed concrete and obtained by concrete mixer truck
DOI:
https://doi.org/10.21814/ecum.4188Abstract
There is a need for the production of homogeneous concretes in order to ensure the quality of the reinforced concrete structures. This fact becomes more relevant, since the assumptions of design calculations consider the structural elements contemplating similar characteristics in any cross section. In this context, there is a guideline expressed in the standard of fresh concrete sampling, NBR NM 33 (ABNT, 1998), which recommends the removal of samples after the discharge of at least 15% of the total volume of the concrete and before discharge of 85 %, so that the degree of homogenization of the concrete can be determined. In contrast
to what the standard recommends, it is known that in most construction works, samples of concrete are collected before the start of concreting. This research aims to verify the homogenization degree of the ready-mixed concrete obtained by concrete mixer truck. For this purpose, the work was carried out in four different construction works, with the consistency index and the mechanical properties of the concretes being verified in two stages: at the beginning of the concreting and at the discharge interval recommended by the standard. It could be verified that there is no significant difference between the concrete collected at the beginning of the concreting and the concrete collected in the interval recommended by the standard.
References
ABECE - Associação Brasileira de Engenharia e Consultoria Estrutural - Estruturas de Concreto - Conformidade da Resistência do Concreto. 2011. Disponível em: www.abece.com.br Acesso em 23 de maio de 2017.
Alves, J. D. Manual de tecnologia do concreto, 3ª Ed. UFG, Goiânia, Brasil (1993).
American Society for Testing Materials. Standard Specification for Ready-Mixed Concrete: ASTM C 94. Philadelphia, 2016.
Associação Brasileira de Normas Técnicas. NBR 12655: Concreto de cimento Portland — Preparo, controle, recebimento e aceitação — Procedimento. Rio de Janeiro, Brasil, (2015).
Associação Brasileira de Normas Técnicas. NBR 5738: Concreto - Procedimento para moldagem e cura de corpos de prova. Rio de Janeiro, Brasil, (2016).
Associação Brasileira de Normas Técnicas. NBR 5739: Concreto - Ensaios de compressão de corpos de prova cilíndricos Rio de Janeiro, Brasil, (2007).
Associação Brasileira de Normas Técnicas. NBR 7222: Argamassa e concreto – Determinação da resistência à tração por compressão diametral de corpos de prova cilíndricos. Rio de Janeiro, Brasil, (2011).
Associação Brasileira de Normas Técnicas. NBR NM 33: Concreto – Amostragem de concreto fresco. Rio de Janeiro, Brasil, (1998).
British Standards Institution – BSI. BS 3963: Method for testing the mixing performance of concrete mixers. UK. (1974).
Ferraris, C. F. Concrete Mixing Methods and Concrete Mixers: State of the Art. Journal of Research of the National Institute of Standards and Technology. v. 106, (2001). DOI: https://doi.org/10.6028/jres.106.016
Helene, P. e Andrade, T. Concreto de cimento portland. In: ISAIA, G. C. (Org). Materiais de Construção Civil e Princípios de Ciência e Engenharia de Materiais. 1. Ed., v.2, IBRACON, São Paulo, Brasil (2007).
Mascolo, R., Masuero A. B., Dal Molin, D. C. C. Concreto usinado: análise da variação da resistência à compressão e de propriedades físicas ao longo da descarga do caminhão betoneira, Revista Ibracon de Estruturas e Materiais, 6(2), 194-210 (2013). DOI: https://doi.org/10.1590/S1983-41952013000200003
Mehta, P. K. e Monteiro, P. J. M. Concreto: Microestrutura, Propriedades e Materiais, 2 nd Ed., IBRACON, São Paulo, Brasil (2014).
Neville, A. M.; Brooks, J. J. Tecnologia do concreto. 2. ed. Porto Alegre, Brasil: Bookman, 448p. 2013.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2022 S.H.M. Mittri, G.L. Vieira, A.A.F. Mendes, G.C. Guignone
This work is licensed under a Creative Commons Attribution 4.0 International License.
