Schleibinger Testing Systems

eBT-V - mobile Rheometer for Fresh Concrete

The eBT-V tested in the Antarctic Sea!

"Frazil ice is the very first ice that forms in the marginal ice zone of the Antarctic. The rheological properties of frazil ice play a significant role in numerical
calculations of sea ice behavior. Up to now no in situ measurements of the rheological properties of frazil ice in the Marginal Ice Zone of Antarctic have been
conducted. The trajectory of the 2019 SCALE Winter Cruise and a test setup for measuring rheological properties in the Marginal Ice Zone of the Antarctic are
presented. A description of a sampler to get undisturbed samples of frazil ice for rheological measurements is explained. The eBT-V rheometer and the modified
vane are presented. Several rheological measurements were conducted in the Antarctic during the Winter Cruise 2019 on the SA Agulhas II."

cited from: 
Experimental setup to determine rheologicalproperties of frazil ice, Felix Paul, Tommy Mielke, Doru C. Lupascu, Institute for Materials Science and Center for Nanointegration Duisburg-Essen
(CENIDE), University of Duisburg-Essen, Germany, felix.paul@uni-due.de, www.uni-due.de/materials/

published in:  
Markus Greim, Wolfgang Kusterle, Oliver Teubert; Rheologische Messungen an Baustoffen 2020, Tagungsband zum 29. Workshop und Kolloquium,11. und 12. März an der OTH Regensburg, ISBN: 978-3-347-02886-9

More info at: https://www.uni-due.de/sea_ice/winter_cruise_2019_bericht.php and https://www.news.uct.ac.za/article/-2019-07-15-polar-cyclones-antarctic-sea-ice-and-a-cruise-to-understand-it-all

 

Application

The eBT-V is a portable compact net-independent rheometer for fresh concrete. In opposite to the spread table or slump flow the concrete is tested at various loads. Therefore you can determine a relative yield stress and a relative viscosity. The eBT-V can be operated in two different modes:

P-mode for the common or vibrated concretes and stiff concretes:
V-mode for modern concretes such as self-compacting or self-consolidating concretes, SCC, and UHPC:

The eBT-V is small, battery driven and easy to use.

 

Design

• compact
• easy and fast change of the operation modies
• cable-free
• the system is driven by a rechargeable battery
• operation control via smartphone (included)
• wireless tranmission of measurement results and display on smartphone
• ideal for quality control and especially for the applications on the building and construction site
• easy to clean

 

How it works:

P-mode:

By the operating the rheometer in P-mode the fresh concrete properties can be investigated due to one single revolution (360 °) in non-sheared concrete. As a result, possible problems such as segregation and structural breakdown during the measurement are greatly minimized. A measuring probe is attached to the measuring instrument and rotated around a centering rod. The force on the probe is measured directly in the probe. The filling level has no influence in the force, as long the probe is covered by fresh concrete. The speed profile is freely programmable. The measurement time is usualy less then one minute.

 

V-mode:

By the operating the rheometer in V-mode the common Vane-geometry as approximation of a classical cylinder geometry will be used. Due to the star arrangement of the wings, the sliding on the wall of the probe is almost completely prevented. Wall slipping on the container surface is also prevented by the use of a device holder with integrated antislip rods. The eBT-V is fixed on the device holder and the Vane probe is attached on the drive shaft. The measuring containter is filled with the sample and the instrument holder with the device mounted on it is placed into container. The Vane probe is rotating and the torque on the Vane probe is measured. The speed profile is freely programmable.

 

• choose the option P- or V- mode
• Fill fresh concrete in the specimen container.
• Switch on the eBT-V, in this moment the force sensors are automatically calibrated.
• Then place the eBT-V on the container.
• Download a free programmable speed profile from your smart phone to the eBT-V.
• Press the start button on your smart phone.
• The eBT-V starts. Wait until the eBT-V stops.
• The data are now non volatile stored in the eBT-V.
• Up to 35 datasets can be stored in eBT-V.
• Afterwards you can transfer the data via the wireless  interface to a smart phone which is delivered with the eBT-V.
• On the smart phone the relative yield stress and relative viscosity are calculated and displayed both numerical and graphical.
• At your office you may transfer this datasets to your notebook ore desktop PC.
• With WiFi or 3G you can also transfer the datasets as an e-mail or with a cloud service like Dropbox (R)  to any place on the world.

 

Five good reasons for the eBT-V:

• Short measurement
• Easy handling
• Portable
• No structural breakdown during the measurement
• no segregation ore sedimentation during the measurement
•  and a very resonable price!

   

 

 

 

 

Another short video (made at the IIT Bombay) shows the operating principle in P-mode

Literature

• Schleibinger Geräte, Mobiles Rheometer für Frischbeton, Prüfung von Baustoffen und Bauteilen, Ernst & Sohn Sonderheft Messtechnik im Bauwesen 2018, S. 64 – 65 (in German)
• Verlag Ernst & Sohn Special Messtechnik im Bauwesen 2017 : Mobiles Rheometer für Frischbeton - Anforderungen an die Betone (in German)
• Markus Greim, Helena Keller, Medida de la reología del hormigón, Revista Téchnica CEMENTO HORMIGÓN, No. 985, Marzo-Abril 2017 (in Spain)
• Greim M., Keller H.: eBT-V - A new rheometer for fresh concrete, Conference Proceedings "Rheology of Building Materials", Regensburg, 2017
• Fleischmann F., Kusterle W.: Neues Rheometer zur Bestimmung der Frischbetoneigeschaften von selbstverdichtenden Betonen, beton [9/2014]
• Lianjun Chen, Guanguo Ma, Guoming Liu, Zhaoxia Liu:  Effect of pumping and spraying processes on the rheological properties and air content of wet-mix shotcrete with various admixtures
• Weisheit, S.;Waldmann,D.;,Greger M. : RHEOLOGIE VON SVB -Untersuchungen am Leim, Mörtel und Beton, ibausil 17. Internationale Baustofftagung Weimar, 2009.
• Fleischmann, F.: Ein Beitrag zur Bestimmung der Rheologischen Eigenschaften Selbstverdichtender Betone mit dem Kugelmesssystem. Dissertation Ruhr-Universität Bochum, Bochum 2014.
• Greim, M.; Teubert O.: Flow characteristics measurement of rough-grained materials such as green concrete Patent DE 19503028 B.
• Greim, M: Rheological Measurement on Building Materials, a Comprehensive Research Program. Annual Transactions of the Nordic Rheology Society , Vol. 5 (1997).
• Gołaszewski, J;INFLUENCE OF MORTAR VOLUME ON THE RHEOLOGICAL PROPERTIES OF FRESH HIGH PERFORMANCE CONCRETE, BFT 10/2008.
• F. Gerland, A. Wetzel, T. Schomberg, O. Wünsch, und B. Middendorf, „A simulation-based approach to evaluate objective material parameters from concrete rheometer measurements“, Applied Rheology, Bd. 29, Nr. 1, S. 130–140, Jan. 2019, doi: 10.1515/arh-2019-0012.

 

Technical data

(subject to change)

	P-Mode	V-Mode
Specimen container	ca. 40 l (alternativ 20 l)	ca. 15 l
specimen container diameter	500 mm	effective 244 mm, cross 270 mm
specimen container depth	200 mm (alt. 100 mm)	290 mm
probes	sphere ∅ 80 mm and cylinder ∅ 32 mm,  height 55 mm	6 blade vane:  ∅ 103 mm, height 103 mm
Maximum torque	10 Nm	10 Nm
Speed range	0.1...40°/s = 0.017 ... 40 rpm
Angular resolution	0.11°
Display	mobile phone
Handling	Power switch + external smart phone (included)
Interface	BT wireless
Power supply	recharchable battery pack
Weight w/o container	ca. 9.9 kg (without battery)

 

Order Codes

 

eBT-V incl. Android running smart phone ©, Incl. accessories: P mode: Specimen container 40 l and shear bodys cylinder and spherical shape.V mode: Vane geometry (vane cell with 6 wings), specimen container 15 l, device holder with 12 antislip rods. 2 battery backs (NiMH), battery charging unit	B0010
20 litres specimen container for the eBT-V made of chromed steel. With 2 handles and a stainless steel gear shaft for the measuring unit. Diameter: 500 mm; height: 100 mm; volume: 19 l, weight: 4.6 kg.	B0003
Four-wheel-trolley for the easy handling of the eBT-V specimen containers (both sizes). Including a dumping mechanism for easy draining the concrete. Easy to disassemble. net weight 8,4 kg.	B0020

 

Resources

Datasheet

User Manual

User Manual for the trolley (pdf)