L-Box Apparatus – GI Steel with Sliding Gate and Reinforcing Bars
Test Equipment for Flowability, Passing Ability and Segregation Resistance of Self-Compacting Concrete (SCC)
GENERAL INFORMATION
| Parameter | Details |
|---|---|
| Equipment Name | L-Box Apparatus |
| Full Form | L-Box Test Apparatus for Self-Compacting Concrete |
| Application | Determination of flowability, passing ability and segregation resistance of Self-Compacting Concrete (SCC) |
| Test Material | Self-Compacting Concrete (SCC) |
| Construction | GI steel L-shaped box with sliding gate and removable reinforcing bar set |
| Gate Type | Sliding gate between vertical and horizontal sections |
| Standards Compliance | EFNARC Guidelines, EN 12350-10 |
EQUIPMENT DESCRIPTION
The L-Box Apparatus is a test equipment used to determine the flowability, passing ability and segregation resistance of Self-Compacting Concrete (SCC). The vertical section is filled with fresh SCC and the sliding gate is lifted, allowing the concrete to flow through the reinforcing bars into the horizontal section. The height of concrete at the end of the horizontal section (H2) is compared with the height in the vertical section (H1) to give the L-Box ratio, indicating how well the mix passes through congested reinforcement without blocking or segregating.
MAIN COMPONENTS
1. Vertical Section (Filling Hopper):
- GI steel section, 200 mm × 100 mm × 700 mm, into which SCC is filled
- Smooth internal surface for consistent flow
- Rigid construction to prevent distortion during testing
2. Horizontal Section (Flow Channel):
- GI steel section, 200 mm × 100 mm × 700 mm, through which SCC flows
- Provides the flow path for measuring the final concrete height (H2)
3. Sliding Gate:
- Separates the vertical and horizontal sections during filling
- Lifts vertically to release the concrete for the flow test
4. Reinforcing Bar Set:
- 3 bars of 12 mm diameter fitted at the gate opening
- Clear spacing of 41 mm ± 1 mm to simulate congested reinforcement
TECHNICAL SPECIFICATIONS
| Parameter | Specification |
|---|---|
| Standard | EFNARC Guidelines, EN 12350-10 |
| Material | GI Steel |
| Vertical Section Dimensions | 200 mm × 100 mm × 700 mm |
| Horizontal Section Dimensions | 200 mm × 100 mm × 700 mm |
| Height of Vertical Section | 700 mm |
| Gate Type | Sliding Gate |
| Reinforcing Bars Diameter | 12 mm |
| Number of Bars | 3 Bars |
| Clear Spacing Between Bars | 41 mm ± 1 mm |
| Measurement Accuracy | 1 mm |
| Test Material | Self-Compacting Concrete (SCC) |
| Test Result | L-Box Ratio (H2/H1) |
| Acceptance Range | 0.80 – 1.00 |
TEST PROCEDURE (SUMMARY)
- Place the apparatus on a firm, level surface and close the sliding gate.
- Fill the vertical section with fresh SCC without vibration or tamping.
- Allow the concrete to rest for the period specified in the standard.
- Lift the gate and let the concrete flow through the bars into the horizontal section.
- Once flow stops, measure the heights H1 (vertical section) and H2 (end of horizontal section).
- Calculate the L-Box ratio H2/H1 and compare it with the acceptance range.
SAFETY & QUALITY FEATURES
- Rigid GI steel construction for stability and dimensional accuracy
- Smooth, deburred edges to protect the operator
- Corrosion-resistant GI material suitable for wet laboratory use
- Precisely spaced reinforcing bars for repeatable passing-ability results
- Smooth-operating sliding gate for controlled release of concrete
- Measurement accuracy of 1 mm for reliable readings
OPERATING FEATURES
- Simple operation with a single sliding gate
- Suitable for laboratory and on-site SCC quality control
- Easy to clean after use and low maintenance
- Repeatable results in line with EFNARC and EN 12350-10
ENVIRONMENTAL SPECIFICATIONS
| Parameter | Range |
|---|---|
| Operating Temperature | 5°C – 50°C |
| Relative Humidity | Suitable for wet and humid laboratory conditions |
| Installation / Use Location | Laboratory, precast yard and site testing areas |
APPLICATION AREAS
- Concrete testing and quality control laboratories
- Construction material research facilities
- Ready-mix and precast concrete plants
- Highway, bridge and infrastructure project sites
- University and research institutions
- SCC mix design and trial mix evaluation
MAINTENANCE SCHEDULE
Daily Maintenance: Clean the apparatus immediately after use, remove all concrete residue, check gate movement and bar condition.
Monthly Maintenance: Inspect welds, bars and gate guides for wear or damage, check bar spacing (41 mm ± 1 mm), lightly lubricate gate guides.
Yearly Maintenance: Complete dimensional and structural inspection, verify calibration of dimensions, repair or replace damaged parts.
WARRANTY
Warranty Period: 12 Months (1 Year) from date of installation or invoice.
