U-Box Test Set evaluates the passing and filling ability of self-compacting concrete (SCC) through confined and reinforced sections. Fresh concrete flows from the filling chamber into the second compartment under its own weight. After the flow stops, the operator measures the concrete heights in both chambers and compares the results. The system includes three Ø12 mm stainless-steel reinforcing bars to simulate congested reinforcement and assess the blocking behaviour of SCC mixtures.
- Application: Testing the passing and filling ability of self-compacting concrete
- Concrete Type: Self-Compacting Concrete (SCC)
- Test Principle: Concrete flows between two compartments under its own weight
- Reinforcement Simulation: 3 × Ø12 mm stainless-steel bars
- Sliding Gate: Provides controlled release of concrete between the chambers
- Evaluation: Comparison of concrete heights in the two compartments
- Construction: Durable stainless-steel contact surfaces
- Stable Support System: Rigid frame helps keep the apparatus stable during testing
- Overall Dimensions: 65 × 65 × 110 cm
- Approximate Weight: 20 kg
- Standard: UNI 11044
| Product Code | Product Name | Overall Dimensions (cm) | Weight (kg) |
| LT-C0057 | U-Box Test Set | 65 × 65 × 110 | 20 |
LT_BETON_UKUTUSU_
What Is a U-Box Test Apparatus?
The U-Box Test Apparatus evaluates the movement of self-compacting concrete through confined and reinforced sections. Fresh concrete flows from one chamber to the other under its own weight. This process allows laboratories to examine the passing and filling ability of an SCC mixture.
High flowability alone does not guarantee good SCC performance. The concrete must also pass through reinforcement without excessive blocking and fill confined spaces effectively. Therefore, the U-Box test provides useful information about concrete behaviour under conditions that simulate congested reinforcement.
How Is the U-Box Test Performed?
First, the operator closes the sliding gate between the two compartments. Fresh concrete is then placed into the filling chamber.
After the required resting period, the operator opens the gate. The concrete flows through the reinforcing bars and enters the second chamber under its own weight.
When the flow stops, the operator measures the concrete height in both sections. The two values are then compared.
A smaller difference between the final concrete heights generally indicates better filling and passing performance. In contrast, a larger difference may suggest that the mixture has difficulty passing through the reinforced section.
Simulation of Reinforced Sections
The apparatus includes three Ø12 mm stainless-steel bars. These bars simulate congested reinforcement in concrete structures and create a controlled obstruction during the test.
As the concrete passes between the bars, the test reveals how easily coarse aggregate and mortar move through restricted openings. Aggregate grading, mortar volume and mixture viscosity can all influence this behaviour.
Therefore, laboratories can use the results to compare different SCC mix designs and identify mixtures that show a greater tendency toward blocking.
Stainless-Steel Construction and Stable Frame
The concrete-contact surfaces feature a durable stainless-steel construction. The smooth internal surfaces support consistent concrete movement and also simplify cleaning after each test.
A rigid support structure keeps the apparatus stable throughout the procedure. This stability helps reduce unwanted movement while the operator releases the concrete and takes the final measurements.
The LT-C0057 has overall dimensions of 65 × 65 × 110 cm and an approximate weight of 20 kg.
Use in SCC Quality Control
The U-Box method can support quality-control and development work for self-compacting concrete. It is particularly useful when engineers need to evaluate mixtures intended for densely reinforced or geometrically restricted structural elements.
However, one test cannot describe every aspect of SCC workability. For a broader evaluation, laboratories can combine U-Box results with slump-flow, V-funnel or L-box testing. In this way, filling ability, passing ability, viscosity-related behaviour and blocking tendency can be assessed together.
Testing According to UNI 11044
The U-Box Test Set is referenced to UNI 11044 for the evaluation of self-compacting concrete.
The test provides a straightforward method for comparing concrete levels before and after passage through a reinforced section. Therefore, laboratories can use the measured height difference as a practical indicator when evaluating SCC mixtures.
As a result, the U-Box Test Apparatus combines a simple test procedure, reinforced-section simulation and robust construction in one practical system. It provides laboratories with an effective solution for evaluating the passing, filling and blocking behaviour of self-compacting concrete.
