Viscosity of Portland cement paste as a function of concentration

Struble, Leslie J.; Sun, Guokuang

doi:10.1016/1065-7355(95)90026-8

Cited by 164 publications

(91 citation statements)

References 16 publications

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“…In case of concrete, as the constituents deviate from spherical shape, modified intrinsic viscosity values should be used to simulate the effects of particle shape. According to Struble and Sun (1995) and Barnes et al (Walters 1989), the intrinsic viscosity is 2.5 for spherical particles, and when the particles deviate from spherical shape, this value should be increased. The intrinsic viscosity is the limiting value of the reduced viscosity as the concentration of particles approaches zero.…”

Section: Effects Of Particle Shapementioning

confidence: 99%

Prediction of Concrete Pumping Using Various Rheological Models

Choi

Kim

2014

Int J Concr Struct Mater

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When concrete is being transported through a pipe, the lubrication layer is formed at the interface between concrete and the pipe wall and is the major factor facilitating concrete pumping. A possible mechanism that illustrates to the formation of the layer is the shear-induced particle migration and determining the rheological parameters is a paramount factor to simulate the concrete flow in pipe. In this study, numerical simulations considering various rheological models in the shear-induced particle migration were conducted and compared with 170 m full-scale pumping tests. It was found that the multimodal viscosity model representing concrete as a three-phase suspension consisting of cement paste, sand and gravel can accurately simulate the lubrication layer. Moreover, considering the particle shape effects of concrete constituents with increased intrinsic viscosity can more exactly predict the pipe flow of pumped concrete.

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Section: Effects Of Particle Shapementioning

confidence: 99%

Prediction of Concrete Pumping Using Various Rheological Models

Choi

Kim

2014

Int J Concr Struct Mater

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“…In effect, the intrinsic viscosity represents the effects of the individual particle shape on the viscosity. According to Struble and Sun (1995) and Barnes et al (1989), the intrinsic viscosity is 2.5 for spherical particles, and when the particles deviate from spherical shape, this value should be increased. The well-known Einstein equation is the original form for the dilute suspension of spherical particles.…”

Section: Determination Of Particle Shape Effects According To the Coamentioning

confidence: 99%

“…There have been various studies indicating that the rheological properties of concrete are affected by the aggregate characteristics, which may be a function of the particle size, concentration, shape and surface texture (Hu and Wang 2011;Tattersall and Banfill 1983;Tattersall 1991;Ferraris 1999;Struble and Sun 1995;Geiker et al 2002;Mahaut et al 2008, Denis et al 2002Kurokawa et al 1996). However, most studies have focused on the effects of the aggregate characteristics on the rheological properties of mortar or concrete itself.…”

Section: Introductionmentioning

confidence: 99%

Numerical Prediction on the Effects of the Coarse Aggregate Size to the Pipe Flow of Pumped Concrete

Choi

2014

ACT

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The objective of this study is to numerically investigate the effects of coarse aggregate size on the pumpability of concrete. In actual construction of super-structures, the coarse aggregate size plays a determining factor on concrete pumping. Thus, depending on the coarse aggregate sizes, the properties of lubrication layer which is the major role facilitating concrete pumping, were numerically simulated using shear-induced particle migration analysis. Moreover, the particle shape effects according to the coarse aggregate sizes were also considered in numerical simulation to precisely simulate the actual flow conditions. For verification, 1,000m long full-scale tests with three different coarse aggregate sizes (10, 20 and 25mm) were conducted and compared with numerical results. It could be found that when concrete is being pumped, the rheological properties of concrete and lubrication layer highly depend on the coarse aggregate size, which consequently influences the flow condition of pumped concrete, whereas the thickness of lubrication layer remained almost constant irrespective of the coarse aggregate sizes.

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“…Para las suspensiones de CL se han obtenido distintos valores de fracción sólida máxima (ϕ m ) y viscosidad intrínseca ([η]) a distintas velocidades (Tabla 4). El aumento del valor de fracción sólida máxi-ma se atribuye a la habilidad de las partículas de empaquetarse en estructuras más densas al estar sometidas a velocidades de cizalla más altas (32). En efecto, las partículas tienden a desaglomerarse durante el cizallamiento, con lo cual es posible un empaquetamiento aún más denso.…”

Section: Viscosidad Intrínseca Y Fracción Máxima De Empaquetamientounclassified