Concrete Box Test Device

Concrete Box Test Device for Reliable Slip Form Concrete Testing

The Concrete Box Test Device is an essential tool designed to quickly and accurately evaluate the workability of slip-formed concrete used in paving applications. This device ensures that concrete pavement mixtures meet the necessary standards for both consolidation and stability during slip-form paving. Proper workability is critical for achieving durable, high-quality pavement as it allows the concrete to consolidate under vibration and hold its shape without slumping after placement.

Why Workability Matters

Concrete used in slip-form paving must balance two key properties:

• Consolidation: The mixture must be able to compact properly under a standard amount of vibration, ensuring the removal of air pockets and voids.
• Stability: The concrete must maintain its shape and edge after placement, which is vital for creating smooth pavement surfaces.

Inconsistent aggregate sizes, improper water-to-cement ratios, or variations in mix designs can lead to issues like surface voids, edge slumping, and overall reduced pavement durability. The Concrete Box Test Device helps mitigate these risks by providing an easy method to test and adjust concrete mixture workability before actual paving begins.

How the Device Works

The Concrete Box Test Device consists of a sturdy platform with form positioning pins, two interlocking box halves, and a ratcheting strap. Here's how it operates:

1. The two interlocking halves are secured on the platform using the positioning pins.
2. The ratcheting strap is wrapped around the box and tightened to hold the formwork together, ensuring no leakage during the test.
3. Fresh, unconsolidated concrete is poured into the assembled box form to a standard depth of 9.5 inches (241.3 mm).
4. A vibrator (purchased separately) with a 1-inch diameter shaft and frequency of 11,500–12,500 vpm is used to consolidate the concrete.
5. After consolidation, the box halves are removed, and the sample is inspected for edge slumping and surface voids. A straightedge helps assess the degree of slumping, while the sides are checked for inconsistencies.

This precise process gives engineers and contractors a clear understanding of the concrete’s performance under real paving conditions.

Product Construction

The Concrete Box Test Device is built for durability and field use. Its key design features include:

• High-Quality Materials: Constructed from 1/2-inch thick plywood that is powder-coated for a smooth, wear-resistant finish.
• Heavy-Duty Components: The pins, latches, and handles are made of rugged metal to withstand repeated use.
• Efficient Design: Lightweight and portable for easy transport to job sites, and the included ratcheting strap provides secure and quick assembly.

When assembled, the device’s internal testing dimensions are 12 x 12 x 12 inches (300 x 300 x 300 mm). The overall product dimensions are 24 x 24 x 12.5 inches (610 x 610 x 317.5 mm), making it compact enough for mobile use while offering ample space for precise testing.

Key Features

• Obtains fast and accurate workability results for slip-formed concrete.
• Durable and wear-resistant construction for long-term use.
• Easy to assemble, lightweight, and portable for field applications.
• Helps identify and prevent issues like surface voids and edge slumping.

Included Items

• Concrete Box Test Device
• Ratcheting strap for secure formwork

Specifications

• Specimen Size: 9.5 inches (241.3 mm)
• Inside Dimensions: 12 x 12 x 12 inches (300 x 300 x 300 mm) LxWxH
• Overall Dimensions: 24 x 24 x 12.5 inches (610 x 610 x 317.5 mm) WxDxH

Standards Compliance

The Concrete Box Test Device meets AASHTO T 396 standards for slip-form concrete testing, making it a reliable and industry-approved choice for pavement projects.

Additional Information

For optimal use, a compatible vibrator with a 1-inch diameter shaft and frequency of 11,500–12,500 vibrations per minute (vpm) is required, which can be purchased separately. Regular testing with this device ensures your concrete mixtures meet the required standards for strength, durability, and paving performance.

Whether you’re testing for a small road project or a large highway, the Concrete Box Test Device is your dependable partner for ensuring high-quality pavement every time.