Toward a rationalization of the slump test for fresh concrete: Comparisons of calculations and experiments

Schowalter, W. R.; Christensen, G. N.

doi:10.1122/1.550905

Cited by 103 publications

(43 citation statements)

References 3 publications

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“…Thus enhanced mix design tools and proper accounting for agglomeration should allow the prediction of the yield stress of concrete and from there the slump test that most norms are based on and which still constitutes a go~no go criterion in field applications. [ 15] with authorisation). Below: a cylinder used for paste tests (reproduced from [16] with authorisation).…”

Section: Prediction O F Concrete S L U M Pmentioning

confidence: 98%

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Towards a prediction of superplasticized concrete rheology

Flatt¹

2004

Mat. Struct.

125

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The rheology of concrete is influenced by water content, the amount, size and size distribution of all the solid components as well as by the dispersion of the finer particles through the addition of superplasticizers. In addition, the rheological behaviour over time evolves as a result of cement hydration. Consequently the a-priori prediction of concrete rheology is a complex task.In this article, models that have been and are being developed to achieve this task are discussed. The key role of the degree of dispersion will be underlined. A treatment of interparticle forces and a yield stress model integrating these will be presented. Such work is necessary to integrate the dispersion efficiency of superplasticizers based on their dosage and molecular structures into existing models for predicting concrete rheology. RESUMI~

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Section: Prediction O F Concrete S L U M Pmentioning

confidence: 98%

“…Recently mathematical approaches have succeeded in describing the evolution of slump value with yield stress [15,16]. In Fig.…”

Section: Prediction O F Concrete S L U M Pmentioning

confidence: 99%

Towards a prediction of superplasticized concrete rheology

Flatt¹

2004

Mat. Struct.

125

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“…In civil engineering, the slump test is commonly used to determine the flow features of concrete and has given rise to abundant literature on empirical yield stress measurement [1][2][3][4][5][6]. A similar test, referred to as the Bostwick test, is widely used in the food industry to characterize the consistency of food products.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of the spreading of viscoplastic fluids on inclined planes

Cochard

Ancey

2009

Journal of Non-Newtonian Fluid Mechanics

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a b s t r a c tWe report experimental results related to the dam-break problem for viscoplastic fluids. Using image processing techniques, we were able to accurately reconstruct the free-surface evolution of fixed volumes of fluid suddenly released a plane. We used Carbopol Ultrez 10 as a viscoplastic material; its rheological behavior was closely approximated by a Herschel-Bulkley model for a fairly wide range of shear-rates. Varying the Carbopol concentration allowed us to change the yield stress and bulk viscosity. The yield stress ranged from 78 to 109 Pa, producing Bingham numbers in the 0.07-0.35 range. We investigated the behavior of a 43-kg mass released on a plane, whose inclination ranged from 0 • to 18 • . For each run, we observed that the behavior was nearly the same: at short times, the mass accelerated vigorously on gate opening and very quickly reached a nearly constant velocity. At time t = 1 s, independently of plane inclination and yield stress, the mass reached a near-equilibrium regime, where the front position varied as a power function of time over several decades. We did not observe any run-out phase, during which the mass would have gradually come to a halt. The similarity in the flow behavior made it possible to derive an empirical scaling for the front position in the form x f = t 0.275(sin˛) 1/3 (sin˛) 5/4 , where˛and t denote plane inclination and time, respectively, and which holds for sloping beds (˛> 0).

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“…It is important to remark that several studies from the literature propose simplified formulations to indirectly estimate the rheological properties of concrete based on the results of the conventional (21,22) or the modified consistency test (23) using the Abrams cone.…”

Section: Rheological Parameters Measured With the Bml -Viscometermentioning

confidence: 99%

“…Con respecto a la viscosidad, los resultados obtenidos (Tabla 2) no muestran una concordancia con la cantidad de pasta (como en el caso de la tensión umbral) ni con la consistencia, a pesar de la existencia de diversos estudios relacionados con la estimación indirecta de las propiedades reológicas de hormigones en base a los resultados del ensayo de consistencia (21,22) o del ensayo de cono modificado con la medición de parámetros adicionales que mejoran la correlación con las propiedades reológicas del hormigón (23) (En el caso de los morteros, la medición de la consistencia no se hace con el cono de Abrams, sino con la mesa de sacudidas).…”

Section: Rheological Parameters Measured With the Bml -Viscometerunclassified

Caracterización de los morteros de relleno usados en diferentes túneles españoles

Cavalaro¹,

Aguado²

2012

Mater. construcc.

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SUMMARYThe main objective of this paper is to compare typical backfill mortars used in Spanish tunnels to fill the annular void left between the lining and the ground by the TBM. Initially, a new experimental program is outlined using material corresponding to 6 mixes from 4 tunnels. The results obtained indicate a considerable difference in the density and in the rheological properties of the mixes tested. According to the estimations performed, this leads to a difference of up to 67% on the potency required from the pumps to inject the material. Furthermore, a correlation between the fine content and the rheological properties of the mix was observed. This correlation may be a practical tool to control and modify the performance of the mortars directly in the worksite.Keywords: mortar; yield stress; viscosity; tunnel boring machine; tunnel. RESUMENEl objetivo principal del presente estudio es llevar a cabo la comparación de las dosificaciones de mortero de relleno empleadas en algunos de los grandes túneles españoles para rellenar el hueco anular dejado entre el terreno y el extradós de las dovelas. Inicialmente se hace una nueva propuesta experimental usando la composición y los materiales correspondientes a 6 dosificaciones usadas en 4 túneles. Los resultados obtenidos indican diferencias significativas en cuanto a la densidad, a la consistencia y a las propiedades reológicas. De acuerdo con las estimaciones realizadas, ello se traduce en diferencias de hasta un 67% en la potencia requerida del sistema de bombas de la tuneladora para inyectar el material. Por otro lado, se refleja una correlación entre el contenido de finos de la mezcla y las propiedades reológicas. Esa correlación puede servir para controlar y modificar dichas propiedades de manera fácil y rápida a pie de obra.

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Toward a rationalization of the slump test for fresh concrete: Comparisons of calculations and experiments

Cited by 103 publications

References 3 publications

Towards a prediction of superplasticized concrete rheology

Towards a prediction of superplasticized concrete rheology

Experimental investigation of the spreading of viscoplastic fluids on inclined planes

Caracterización de los morteros de relleno usados en diferentes túneles españoles

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