L-Box Test Set evaluates the passing ability of self-compacting concrete (SCC) through reinforcement-like obstacles. Fresh concrete flows from the vertical chamber into the horizontal section under its own weight. The operator compares the concrete heights at two points to determine the passing ratio. The adjustable barrier system can be configured with two or three Ø12 mm steel bars, allowing laboratories to simulate different reinforcement densities and observe potential blocking behaviour.
- Product Code: LT-C0056
- Product Name: L-Box Test Set
- Application: Passing ability testing of self-compacting concrete
- Concrete Type: Self-Compacting Concrete (SCC)
- Test Principle: Measures concrete flow through reinforcement-like obstacles
- Barrier System: 2 or 3 steel bars, Ø12 mm
- Three-Bar Clearance: 41 ±1 mm
- Two-Bar Clearance: 59 ±1 mm
- Evaluation: Passing ratio calculated from two concrete height measurements
- Sliding Gate: Provides rapid and controlled concrete release
- Complete Set: Includes filling chamber and support stand
- Overall Dimensions: 30 × 100 × 135 cm
- Approximate Weight: 35 kg
- Standard: EN 12350-10
| Product Code | Product Name | Overall Dimensions (cm) | Weight (kg) |
| LT-C0056 | L-Box Test Set | 30 × 100 × 135 | 35 |
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What Is an L-Box Test Apparatus?
The L-Box Test Apparatus determines the passing ability of self-compacting concrete through reinforcement-like obstacles. Fresh concrete flows from a vertical chamber into a horizontal channel under its own weight. This process allows laboratories to evaluate how effectively the mixture passes through restricted areas.
High flowability alone does not guarantee good SCC performance. The concrete must also pass through reinforcement without significant blocking. Therefore, the L-Box test provides a numerical method for assessing this behaviour.
Adjustable Barrier System
The apparatus uses Ø12 mm steel bars to simulate reinforcement. The operator can configure the system with either two or three bars according to the required test arrangement.
With three bars, the clear spacing is 41 ±1 mm. With two bars, the spacing increases to 59 ±1 mm.
This adjustable configuration allows laboratories to represent different reinforcement densities. It also helps users observe how aggregate size, mortar volume and mixture viscosity influence passing behaviour.
How Is the L-Box Test Performed?
First, the operator closes the sliding gate and fills the vertical chamber with fresh self-compacting concrete.
After the required resting period, the gate opens quickly and smoothly. The concrete then passes between the steel bars and flows along the horizontal channel.
When the flow stops, the operator measures the concrete height at two different locations. One measurement is taken near the vertical section, while the second is taken at the end of the horizontal channel.
The user then compares these values to calculate the passing ratio.
A higher ratio generally indicates better passing ability. In contrast, a lower value may indicate blocking or restricted movement through the reinforcement.
Evaluation of Blocking Behaviour
The barrier system allows laboratories to observe the interaction between coarse aggregate and restricted openings.
If the mixture contains insufficient mortar or unsuitable aggregate grading, coarse particles may accumulate around the bars. As a result, the concrete may fail to flow evenly through the obstruction.
For this reason, the L-Box test is useful during SCC mix development and quality-control studies. Laboratories can compare different formulations under the same test conditions and identify mixtures with better passing performance.
Easy-to-Clean and Rigid Construction
The vertical chamber and horizontal channel are designed for straightforward cleaning after each test. Regular cleaning helps the sliding gate move freely and keeps the internal dimensions consistent.
The rigid structure also keeps the apparatus stable during filling and concrete release.
The LT-C0056 has overall dimensions of 30 × 100 × 135 cm and an approximate weight of 35 kg. The system is supplied with the filling chamber and support stand required for the test arrangement.
Use According to EN 12350-10
EN 12350-10 specifies the L-Box method for determining the passing ability of self-compacting concrete.
The test uses the difference between concrete heights in the apparatus to evaluate the ability of the mixture to flow through reinforcement-like restrictions.
Therefore, the method provides laboratories with a practical numerical indicator for comparing SCC mixtures.
Reliable SCC Passing Ability Testing
The L-Box Test Apparatus combines an adjustable reinforcement barrier, straightforward height measurement and a rigid test structure.
As a result, laboratories can evaluate the passing ability and blocking behaviour of self-compacting concrete in a controlled and repeatable manner. The adjustable two- or three-bar configuration also provides flexibility when simulating different reinforcement conditions.
