Flooring revamped to support high-density storage
22 March 2018
One of the world’s largest capital goods companies recently upgraded its logistics operations and brought in the Cogri Group to ensure the flooring was up to scratch.
A complete reconfiguration of the racking system and installation of the latest in vertical storage and automation technology from Kardex has delivered incredible efficiencies and additional storage capacity for the client at its St Mary’s warehouse, just outside Sydney, Australia.
Installation of the Vertical Carousel and Shuttle System was a compelling investment by improving productivity and throughput, whilst increasing storage capacity and significantly reducing the footprint required to store the stock. The extra space available enabled additional racking to be installed including VNA (very narrow aisle) racking, further increasing capacity.
With all the additional storage, demands on the floor quickly became a problem. The existing warehouse is an old facility dating back around 50 years and the slab was never designed to take the loads of the Kardex System or the condensed racking configuration.
Face Consultants were contacted to assess the floor loading capabilities, this involved taking core samples, running laboratory tests on the cores to determine the compressive strength and then analysing the results against the requirements of the racking and Kardex systems. In additional, a Profileograph survey was carried out to review the slab for suitability for VNA use.
The results of the tests revealed slab thicknesses ranged between 120mm to 150mm with varying compressive strengths. The short fall in structural capacity of the floor was a major set-back for our client. The option to completely demolish and rebuild a new slab was seriously considered but the cost of construction and the significant disruption it would cause the business quickly ruled it out.
Face Consultants were asked to provide a solution that would not impact operations or the critical deadline for installation of Kardex system.
In other parts of the world, Face has designed (and through our contracting division, CoGri) they have constructed and upgraded hundreds of warehouse floors. Drawing on our global experience, Face proposed cutting and removing two sections of floor to upgrade the slab to take the loads of Kardex Carousel and Shuttle System, using a Face designed slab.
Where the majority of the VNA racking and wide aisle racking was to be installed, Face Consultants designed concrete plinths to sit on top of the slab to which the racking would then be fixed. It sounds like a brilliantly simple solution to a potential expensive demolition and reconstruction job, but it was far more complicated than just building a slab-on-slab. For one, the floor levels in some sections were out by as much as 60mm across a construction joint, and you then need to consider how the MHE would need to operate with the new plinth to name just a couple of challenges. This was all before you had to consider construction of the plinths themselves, in a fully operational warehouse with limited access. This is where CoGri Australia was introduced to provide the required expertise to deliver the solution.
With the loading issue sorted for the racking and the Carousel and Shuttle System, assessment of the floor for the VNA racking revealed another issue. Analysis of the flatness showed the floor was not suitable for the safe operation of the very narrow aisle MHE (material handling equipment), for the heights they will be required to operate.
A simple and effective solution would have been to laser grind the floor using CoGri’s patented Laser Grinder technology, however, to achieve the F-min flatness specification would mean grinding as much as 15-20mm off the floor in some areas, and whilst this is common and easily achieved using the Laser Grinder, the already thin floor could not be reduced any further. Even though the racking had been upgraded to take the new loads, reducing the thickness of the VNA slab where the MHE would operate in the aisles was not possible.
Industrial grade floor screed
Despite Laser Grinding being the ultimate upgrade to a floor for VNA use, the only solution left available was to apply an industrial grade screed system. Upgrading a floor to meet the Fmin VNA flatness specification using a screed system is not as simple as just pouring a self-smoothing (often, and wrongly, referred to as self-levelling) screed; because simply laying a self-smoothing screed to a floor without consideration of the flatness levels required will not guarantee the floor will meet the specification. Furthermore, some screed systems can introduce static build-up, and with repetitive traffic along the defined path, they can wear resulting it tracks in the floor, and there is also risk of the screed delaminating. Ultimately, though, a self-smoothing screed would not meet the flatness specification for VNA use.
Through Face and CoGri’s extensive experience in super-flat floors, the screed system was laid to the required F-min flatness tolerance. A survey was taken of the floor using a precise optical level and PPM (Precision Plate Micrometre), the results analysed and then a flatness profile was then plotted on the floor using a series of screws adjusted precisely to meet the F-min specification. The screed was then poured and carefully finished to the new flatness profile and checked for compliance.
CoGri’s FASTFLOOR-IT Screed System is a unique cementitious pump screed used to upgrade industrial floors for all types of use, and with an abrasion resistance rating exceeding AR1, wearing risk of the surface is almost totally eliminated.
Across the remaining floor area, through years of use, many of the floor joints were in need of repair. Cracks, joint repairs and spall damage was repaired by CoGri, including additional joint repairs to the external slab that connected the existing warehouse and to a recent extension.
Overall, Face Consultants and CoGri Australia was able to provide our client with a low impact, reduced cost solution to upgrade their floor to install the latest automated equipment and condensed racking configuration to meet their logistical operational needs for years to come.
Summary of service provided