Efflux Index Apparatus | Flow Coefficient
STANDART: TS EN 932-2; ASTM C702; BS 812:1, 1377:1, 1924:1
LT-A0049 Efflux Index Apparatus | Flow Coefficient
Efflux Index (Flow Coefficient) Apparatus is designed to determine the flow coefficient of fine aggregates and to provide information about particle shape, angularity and surface characteristics. The test measures the time required for a specified volume of aggregate to pass through a defined opening under controlled conditions. Its simple mechanical construction allows quick, consistent and repeatable laboratory measurements.
- Flow Coefficient Measurement: Determines the flow behaviour of fine aggregate particles.
- Fine Aggregate Assessment: Provides information about particle shape and angularity.
- Surface Characterisation: Supports evaluation of aggregate surface characteristics.
- Timed Flow Method: Measures the time required for a specified aggregate volume to pass through a defined aperture.
- Flow Control Cover: Allows the material discharge to start in a controlled manner.
- Cylindrical Feed Chamber: Holds the prepared aggregate sample before testing.
- Integrated Funnel: Directs the aggregate through the required flow opening.
- Metal Stand: Keeps the test assembly stable during measurement.
- Mechanical Operation: Requires no electrical power supply.
- Compact Dimensions: 150 × 180 × 410 mm.
- Weight: Approximately 5 kg.
- Product Code: LT-A0049.
- Standard: EN 933-6.
| Product Code | Product Name | Dimensions (mm) | Weight (kg) |
| LT-A0049 | Efflux Index (Flow Coefficient) Apparatus | 150 × 180 × 410 | 5 |
LT_EFFLUXINDEX_
What Is an Efflux Index (Flow Coefficient) Apparatus?
The Flow Coefficient Apparatus is used to evaluate the flow characteristics of aggregates under defined laboratory conditions. For fine aggregates, the test provides useful information about particle shape, angularity and surface texture by measuring how quickly a specified volume of material passes through a standard opening.
The flow coefficient is expressed using the measured discharge time. Therefore, laboratories can compare aggregate samples using the same controlled test arrangement. Liya Test supplies the unit as the LT-A0049 Efflux Index (Flow Coefficient) Apparatus.
Flow Coefficient Measurement
The test uses a cylindrical feed chamber and a defined discharge opening. First, the operator prepares the aggregate sample according to the applicable procedure. The sample is then introduced into the feed chamber.
Once the flow control cover is released, the aggregate passes through the funnel. The operator measures the required discharge time in seconds. This value provides the basis for determining the flow coefficient.
Particle geometry directly affects this behaviour. Angular or rough-textured particles may move differently from smoother and more rounded particles. Therefore, the method provides useful information when comparing aggregate sources.
Simple Mechanical Test System
The apparatus consists of a flow control cover, cylindrical feed chamber, cylindrical body, funnel and metal stand. Its fully mechanical design requires no electrical connection or electronic controller.
This simple construction also makes preparation and cleaning straightforward. The operator can complete repeated tests without complex machine setup.
The LT-A0049 measures 15 × 18 × 41 cm and weighs approximately 5 kg, making it suitable for routine laboratory use.
Aggregate Shape and Surface Characteristics
Flow behaviour depends not only on particle size but also on particle shape and surface texture. For this reason, the result can assist laboratories when comparing aggregates from different production sources.
However, the flow coefficient should be interpreted together with other relevant aggregate properties. Particle-size distribution, shape index and crushed-surface characteristics may also influence overall material performance.
EN 933-6 Standard
The current EN 933-6:2022 standard specifies the reference method for determining the flow coefficient of fine aggregates up to 2 mm and coarse aggregates from 4 mm to 20 mm. BSI lists BS EN 933-6:2022 as the current edition.
The Efflux Index (Flow Coefficient) Apparatus combines a compact mechanical design with a straightforward measurement method. As a result, aggregate laboratories can evaluate flow behaviour in a practical and repeatable manner.
