Concrete Box Test Device

The Concrete Box Test Device provides a quick and accurate method for determining the workability of slip-formed concrete in paving applications. The concrete pavement mixture used in slip-form pavers must be able to adequately consolidate when exposed to a standard amount of vibration while also having enough stability to hold an edge after placement. Consolidation issues caused by inconsistent aggregate sizes or variations in mix designs can leave behind surface voids, affecting pavement quality and durability.

The device is composed of a platform with form positioning pins and two halves of an interlocking box form. The two interlocking box halves include draw latches and latch blocks with threaded rods attached. This design creates a quick and efficient way to secure the box halves together while also ensuring the concrete mixture remains inside the box during the consolidation process.

A fresh, unconsolidated concrete sample is placed in the assembled box mold to a depth of 9.5in (241.3mm). A vibrator with a frequency of 11,500–12,500vpm and a 1in dia. shaft is needed to consolidate the sample and is purchased separately. Once consolidation is complete, the two halves of the box form are removed, and a straightedge is used to observe the degree of edge slumping. The sides of the sample should also be inspected for surface voids.

When assembled, the device’s inside dimensions measure 12in (300mm) along each side. The apparatus is constructed of 1/2in thick plywood with a smooth, wear-resistant powder-coated finish. The draw latches, latch blocks, and handles are all heavy, rugged metal.

Features:

• Provides fast and accurate determinations of slip form concrete workability
• Sturdy, wear-resistant design
• Easy to use and lightweight for mobile use

Included Items:

• Slip Form Concrete Box Test Device

Accessories:

• Stainless Steel Straightedges are constructed of 304 stainless steel and used for trimming or leveling specimens
• HM-135 Concrete Vibrator is used to consolidate freshly molded concrete specimens