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Green mining – use of hydraulic backfill in the Velenje Coal Mine
Published in Ferri Hassani, Jan Palarski, Violetta Sokoła-Szewioła, Grzegorz Strozik, Minefill 2020-2021, 2021
For easy, fairly accurate and fast determination of the consistency (resistance to shape change) of the backfill mixture, we used the measurement of the paste flow on the glass plate or paste flow value measurement. The measurement is taken from civil engineering standards (flow table test or flow test; ASTM C230, DIN EN 12350-5) and is performed at various time intervals. Place a metal cone with a volume of 0.34 dm3 in the middle of a dry glass plate (1 x 1 m) and fill it with the backfill mixture. Raise the cone quickly and measure the diameter resulting flow of the backfill mixture in two perpendicular directions, as shown in Figure 2 (left).
Properties of fresh concrete
Published in Peter Domone, John Illston, Construction Materials, 2018
Apart from only giving a single test value, these four tests (or five if we consider the slump-flow test to be distinct from the slump test) all measure the response of the concrete to specific, but arbitrary and different, test conditions. The slump, slump-flow and flow table tests provide a measure of the fluidity or mobility of the concrete; the slump test after a standard amount of compaction work has been done on the concrete, the slump-flow test after the minimal amount of work of pouring into the cone, and the flow table test with a combination of compaction work and energy input. The degree of compactability test assesses the response of the concrete to applied work, but the amount of work done in falling from the top of the container is much less than the energy input from practical compaction equipment such as a poker vibrator. The Vebe test comes closest to assessing the response to realistic energy levels, but it is the most difficult test to carry out and it is not able to distinguish between the types of high-consistence mixes that are becoming increasingly popular.
Properties of fresh concrete
Published in Marios Soutsos, Peter Domone, Construction Materials, 2017
The flow table test (BS EN 12350-5, Figure 18.5) was devised to differentiate between high workability mixes. It is essentially a slump test with a lower volume of concrete in which after lifting the cone some extra work is done on the concrete by lifting and dropping one edge of the board (or table) on which the test is carried out. A flow or spread of 400 mm indicates medium consistence, and 500 mm or more high consistence.
Heated stone powder substitute for metakaolin-based geopolymer
Published in European Journal of Environmental and Civil Engineering, 2023
Mehmet Akturk, Furkan Turk, Ilker Bekir Topcu, Ulku Sultan Keskin
The flow table test was carried out according to EN-1015-3 (EN-1015-3, 1999). First, the frusto-conical mould is placed in the centre of the flow table. The mould was then completely filled in two steps by tamping ten times in each step. The mould was then slowly pulled vertically upwards. Finally, the table was lowered 15 times, approximately once per second, and the diameter of the spread mortar was measured in two axes and averaged.
Compressive strength and microstructure evolution of low calcium brown coal fly ash-based geopolymer
Published in Journal of Sustainable Cement-Based Materials, 2020
Muhamed Khodr, David W. Law, Chamila Gunasekara, Sujeeva Setunge, Robert Brkljaca
A standard flow table test is conducted in accordance with the ASTM C1437 in order to measure the flowability of each mix design [32]. The compressive strength test is in compliance with ASTM C109/C109M standard, with a total of four specimens being tested and averaged for each data point. The specimens have a loading rate of 0.34 N/mm2/S applied using a Tecnotest concrete testing machine (TCM) and tested until failure.
Prediction of the rheological properties of nanosilica blended self-compacting concrete under the influence of a dispersing agent
Published in European Journal of Environmental and Civil Engineering, 2023
Julian D. Puerto Suárez, Juan Lizarazo-Marriaga, Jhon Cárdenas-Pulido, Sandra Liliana Uribe C., Camilo Higuera
Traditionally, the fresh-state properties of concrete have been measured through the application of indirect methods such as the slump (ASTM C143M, 2020): although it allows to identify some aspects of the flow of a mixture, do not let us to obtain all the physical variables involved. Another traditional method used in civil engineering to assess the properties of mortars in the fresh state (workability) is the flow table test (ASTM C1437, 2020). However, SCC properties, such as viscosity, passing ability, and segregation resistance, cannot be evaluated using the single slump measurement (ACI 238-08, 2008) or the flow table test. Rheological characterisation is also recently becoming common for cement-based materials, because it is possible to simultaneously determine the plastic viscosity and the yield stress for different applied torques. In this regard, the ACI Committee 238 Report relates three types of tests that can be performed on concrete mixtures in order to assess the concrete workability in the fresh state (ACI 238-08, 2008). In the first group, the so-called qualitative methods are included, in which observations are established as a reference. In the second group, there are indirect workability methods, which are normalised and routinely used in the field and laboratory. Finally, the modern methods are those of rheology, in which the physical variables of flow (yield point and plastic viscosity) can be obtained, although some expensive equipment often limited those to a few laboratories (Wallevik & Wallevik, 2011). The yield point represents the stress required to breaking the rest state and produce the flow of the mixture, and the plastic viscosity is the parameter that will dominate the flow after the yield stress has been exceeded. According to Ferraris et al. (2001) and Martins and Bombard (2012), the yield stress correlates with the slump (workability), and the plastic viscosity that represents the properties of pumpability, placement, and finalisation of the concrete, can be correlated with the flow time in the Marsh cone test.