Solution Features and Benefits

• Conventional method for constructing VNA Warehouse floors to tolerance
• Experienced Specialists can construct floor to tolerance without Grinding
• Floor can be constructed to any Defined Traffic Specification
• No Dry Shake required = no risk of delamination!
• Racking layout must be fixed before floor construction

Design and Specification

Design and Construction of Superflat floors is highly specialised and the Client must involve an experienced specialist as early as possible in the project planning stage.  The design of the entire warehouse must be done in consideration to the buildability of a Superflat floor.  VNA tolerances can be achieved by Long Strip using various slab designs including Suspended Slabs, Slabs on Grade and Bonded Toppings.  However due to the very stringent tolerances required, careful consideration is required in relation to deflection during construction, joint layout and crack control.  As the method requires construction joints to be formed below the racking, the VNA racking layout must be fixed prior to the floor construction.

Although the CoGri Group has experience and the expertise to construct Superflat floors to any of the Defined Traffic floor specifications commonly used around the world – including:- the U.K Concrete Society’s TR-34, ASTM E1155 Fmin or DIN 15185, for ease of use and clearly defined limits and Compliance Testing guidelines, CoGri Korea recommends the use of TR-34 (2003) Table 4.3 for Defined Traffic floor flatness specification.  The floor specification should be selected based on the lift height of the VNA truck.  Most importantly it is recommended that to ensure that the Client gets the quality of floor required and paid for, a specialist Superflat testing company is selected to carry out Compliance Testing in accordance with the Specification.

Constructing Superflat floors to tolerance is specialised and risky business.  If the floor fails to achieve the tolerance required to enable the safe and efficient use of the VNA lift trucks at design speed with low maintenance the floor will require remedial grinding work which is expensive and complicated.  Therefore the specification and testing method/ company must be clearly stated and the Client must ensure that the selected Flooring Contractor has experience in constructing floors to the required tolerance – a proven track record.  As the Concrete Quality Control is critical to successful construction of Superflat floors, it is strongly recommended that the Flooring Contractor supplies the concrete in order to provide the Client with single point liability.

Construction Methodology

As with all high quality concrete flooring, the warehouse must be fully enclosed and weatherproof prior to construction of the floor.  As the name suggests the slab is constructed in Long Strips of about 4-5 m wide with construction joints formed below and VNA racking out of the trafficable floor area.  Purpose made adjustable Construction Joint systems are required and specialised high tolerance levelling equipment must be used to level the construction joints to within +/- 0.1 mm of the floor finish level.  The concrete mix design, workability and setting properties must be perfect in order to finish the concrete to the required tolerance.  CoGri Korea Engineers  carry out slump tests on site to every single load of concrete and demand consistency far above general standards.

The concrete is placed, compacted and levelled with reference to the construction joints using a series of procedures carried out by an experienced team of concreters with high levels of supervision by CoGri Korea staff. 

Once the concrete has achieved initial set, CoGri Korea’ highly skilled Superflat Floor Technicians will use a Highway Straightedge to finish the concrete to the required longitudinal tolerance.  Once the Technician is satisfied that the floor is flat enough, Power Trowelling will begin with specialised procedures applied to finish the concrete to a highly burnished and abrasion resistant surface.  Finally an Acrylic Curing Compound and Sealer will be applied.

 Finally an Acrylic Curing Compound and Sealer will be applied.

Unlike some other Flooring Contractors, the experience and expertise of the CoGri Group allows CoGri Korea to construct Superflat floors without the need for a Dry Shake Topping which is sometimes applied to the concrete surface wet as the concrete sets to achieve the required tolerance. 

This method is considered risky as poor timing or inconsistent concrete properties can lead to delamination of the surface.  Unlike many other Flooring Contractors, all CoGri Korea Superflat floors are surveyed using Digital Profileographs in accordance with TR-34 – often with progressive surveys done on a daily basis during construction to give the Client and all involved Peace of mind. 

CoGri Korea and the CoGri Group never compromise on quality when it comes to the construction of Superflat floors!