Medindo densidade de empacotamento e demanda de água do cimento Portland e MCSs pelo método da energia de mistura

Soto, Nicolle Talyta Arriagada; Macioski, Gustavo; Araújo, Emanoel Cunha; Hoppe Filho, Juarez; Klein, Nayara Soares

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ORIGINAL ARTICLE • Rev. IBRACON Estrut. Mater. 16 (5) • 2023 • https://doi.org/10.1590/S1983-41952023000500007 copiar

Medindo densidade de empacotamento e demanda de água do cimento Portland e MCSs pelo método da energia de mistura

Autoria SCIMAGO INSTITUTIONS RANKINGS

Resumo

Os métodos de empacotamento via úmida avaliam a densidade de empacotamento de materiais finos através da determinação da densidade aparente e teor de vazios de pastas com diferentes relações água/sólidos (a/s). Seu objetivo é estimar a demanda mínima de água para atingir a concentração máxima de sólidos na mistura, um parâmetro aplicado à dosagem de compósitos cimentícios utilizando teorias de empacotamento de partículas. Como a maioria dos métodos baseados na densidade aparente são demorados e requerem um grande volume de materiais, este trabalho visa avaliar o método de energia de mistura como uma alternativa ao método de empacotamento via úmida e adaptá-lo para ser usado para MCSs (materiais cimentícios suplementares). Com um tempo reduzido e menor quantidade de material realizar o teste, os resultados demonstram uma melhor precisão do método da energia de mistura, devido à sua medição discreta. O fluxo de água ideal e o volume inicial de materiais para realizar o teste em cimento e MCSs são discutidos.

Palavras-chave:
empacotamento de partículas; pó fino; modelo de empacotamento compressível; Arduino

Method	Evaluation criteria	Reference
Water demand France	Visual assessment of paste consistency	[⁷7 F. De Larrard, Concrete Mixture Proportioning. Boca Raton, FL, USA: CRC Press, 1999. http://dx.doi.org/10.1201/9781482272055. http://dx.doi.org/10.1201/9781482272055... ]
Water demand Germany	Visual assessment of paste saturation point	[⁸8 W. Puntke, “Wasseranspruch von feinen Kornhaufwerken”. Beton-Dusseldorf, vol. 52, no. 5, pp. 242-249, 2002. ] apud [⁹9 S. A. A. M. Fennis, "Measuring water demand or packing density of micro powders: Comparison of methods," in TUDelft Conference, 2008, pp. 21.]
Proctor test	Oven-dry humidity in compacted mixture	[¹⁰10 European Committee for Standardization, Unbound and hydraulically bound mixtures - Part 2: Test methods for laboratory reference density and moisture content - Proctor compaction, EN 13286-2, 2010.], [¹¹11 H. H. C. Wong and A. K. H. Kwan, "Packing density of cementitious materials: part 1—measurement using a wet packing method," Mater. Struct., vol. 41, no. 4, pp. 689-701, May 2008, http://dx.doi.org/10.1617/s11527-007-9274-5. http://dx.doi.org/10.1617/s11527-007-927... ]
Centrifugal consolidation	Excess water after centrifugation	[¹²12 K. T. Miller, R. M. Melant, and C. F. Zukoski, "Comparison of the compressive yield response of aggregated suspensions: pressure filtration, centrifugation, and osmotic consolidation," J. Am. Ceram. Soc., vol. 79, no. 10, pp. 2545-2556, Aug 2005, http://dx.doi.org/10.1111/j.1151-2916.1996.tb09014.x. http://dx.doi.org/10.1111/j.1151-2916.19... ], [¹³13 A. M. Kjeldsen, Consolidation Behavior of Cement‐based systems. Influence of Inter‐particle Forces, Lyngby: Technical University of Denmark, 2007.]
Water demand - Japan	Slump flow test results	[¹⁴14 H. Okamura and M. Ouchi, "Mix design for self-compacting concrete," Concr. Libr. JSCE, vol. 25, pp. 107-120, 1995.]
Rheology - Krieger and Dougherty	Viscosity of the mix	[¹⁵15 S. Mansoutre, P. Colombet, and H. Van Damme, "Water retention and granular rheological behavior of fresh C3S paste as a function of concentration," Cement Concr. Res., vol. 29, no. 9, pp. 1441-1453, Sep 1999, http://dx.doi.org/10.1016/S0008-8846(99)00129-5. http://dx.doi.org/10.1016/S0008-8846(99)... ]
Vicat test	Needle penetration	[¹⁶16 ASTM International, Standard Test Methods for Time of Setting of Hydraulic Cement by Vicat Needle, C191, 2019.]
(Gas) pressure filtration	Pressure variation	[¹⁷17 S. Mansoutre, P. Colombet, and H. Van Damme, "Water retention and granular rheological behavior of fresh C3S paste as a function of concentration," Cement Concr. Res., vol. 29, no. 9, pp. 1441-1453, Sep 1999, http://dx.doi.org/10.1016/S0008-8846(99)00129-5. http://dx.doi.org/10.1016/S0008-8846(99)... ]
Wet packing method	Apparent density of the paste	[¹¹11 H. H. C. Wong and A. K. H. Kwan, "Packing density of cementitious materials: part 1—measurement using a wet packing method," Mater. Struct., vol. 41, no. 4, pp. 689-701, May 2008, http://dx.doi.org/10.1617/s11527-007-9274-5. http://dx.doi.org/10.1617/s11527-007-927... ]
Water demand / mixing energy	Energy consumption during the mixture	[¹⁸18 I. Marquardt, Ein Misschungskonzept für selbstverdichtenden Beton auf der Basis der Volumenkenngrössen und Wasseransprüche der Ausgangsstoffe. Rostock (Germany): Rostocker Berichte, 2002. Beton 4/2002 ab Seite 197.] apud [⁹9 S. A. A. M. Fennis, "Measuring water demand or packing density of micro powders: Comparison of methods," in TUDelft Conference, 2008, pp. 21.] [¹⁹19 L. Marquardt, "Determination of the composition of self-compacting concretes on the basis of the water requirements of the constituent materials - presentation of a new mix concept," Bentonwerk + Fertigteiltechnik - BFT, vol. 11, pp. 22-30, 2002.] apud [²⁰20 M. Hunger and H. J. H. Brouwers, "Flow analysis of water-powder mixtures: application to specific surface area and shape factor," Cement Concr. Compos., vol. 31, no. 1, pp. 39-59, Jan 2009, http://dx.doi.org/10.1016/j.cemconcomp.2008.09.010. http://dx.doi.org/10.1016/j.cemconcomp.2... ]

Material	Specific gravity (g/cm³)	D₅₀ (µm)
Portland cement	3.13	10.99
Fly ash	3.00	44.14
Limestone filler	2.78	43.55
Metakaolin	2.49	18.45
Silica	1.97	0.201

Mixing speed	140 rpm
Container	200ml
w/s ratio (by mass)	0.13 - 0.15 - 0.17 - 0.20 - 0.25 - 0.35
Mixing procedure	50% cement + 80% water + 100% superplasticizer Mix for 3min Add 4x (12.5% cement + 5% water) and mix for 3 min

Initial w/s ratio	0.176 (0.55 in volume)
Cement consumption	1.5 kg	1.0 kg
Water addition rate	1.5ml/s	1.5 ml/s	0.5 ml/s	10ml/20s

Material	Initial dry mass (kg)	Initial w/s ratio (weight)
Portland cement	1.00	0.176
Limestone filler	1.00	0.088
Fly ash	1.00	0.176
Metakaolin	1.00	0.264
Silica	0.75	0.606

Method for adding water to the mix	Packing density (-)	Minimum w/s, by volume (-)	Minimum w/s, by weight (-)
1.5 ml/s with 1.5 kg of cement	0.604	0.628	0.203
1.5 ml/s with 1.0 kg of cement	0.574	0.700	0.227
0.5 ml/s with 1.0 kg of cement	0.597	0.634	0.205
10 ml/20 s with 1.0 kg of cement	0.591	0.652	0.211

Material	Packing density (-)	Minimum w/s, by volume (-)	Minimum w/s, by weight (-)
Portland cement	0.597	0.619	0.194
Fly ash	0.704	0.402	0.200
Limestone filler	0.578	0.704	0.126
Metakaolin	0.455	1.177	0.472
Silica	0.344	1.885	0.677

IBRACON - Instituto Brasileiro do Concreto Instituto Brasileiro do Concreto (IBRACON), Av. Queiroz Filho, nº 1700 sala 407/408 Torre D, Villa Lobos Office Park, CEP 05319-000, São Paulo, SP - Brasil, Tel. (55 11) 3735-0202, Fax: (55 11) 3733-2190 - São Paulo - SP - Brazil
E-mail: arlene@ibracon.org.br

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[1] Corresponding author: Nicolle Talyta Arriagada Soto. E-mail: nicolle.a.soto@gmail.com