Modulblok (r)evolutionary pallet racks

Modulblok has always put advanced research and high-level design at the centre of its company activities, aimed at the development of safe products respecting the strictest, most modern quality standards. The Pallet Rack modular system, which belongs to the category of adjustable pallet racking, special steel structures made of vertical uprights frames linked by horizontal beams with adjustable height, is the result of the application of this company philosophy and years of experience in the international market. The stability of the system is guaranteed by the technical specifications of the mechanism that links the vertical upright frames to the horizontal beams, specially equipped with continuous perforations. To be able to guarantee heavier loads maintaining the safety levels envisioned by current laws it is necessary to understand all the mechanical features of the system in detail: for this reason Modulblok constantly tests what it produces, to verify the quality of its own design while making use of two internal well-equipped laboratories and collaborating with prestigious university institutes in Italy and around the world.

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Having been present in the principal Italian and European standardization committees (UNI, ERF, CEN), Modulblok has for many years put its own experience at the service of good design regulations, as well as remained updated on the changes under way. Careful attention paid to the continual improvement of production standards, concerning quality and safety, has always led Modulblok to be confirmed among the leading firms in Europe to offer products that are consistently in step with the times.

For these reasons, Modulblok is proud to offer you the excellence of its own evolutionary Pallet Rack system.

Modulblok profiles

Many decades of experience in the sector of pallet racks and years of study and collaboration with the most important University Research Centres in Italy and around the world have led to the definition of upright sections and beams that are the most suited to obtain maximum performance with the lightest weight. This means reducing the quantity of raw material used and therefore the general costs including transport and assembly, while maintaining in any case a high degree of safety in working conditions.

Modulblok uprights, built in high-resistant steel specifically suited for cold forming, are available in five different geometries, designed to cover the widest range of needs, from light loads to those that are very heavy and with applications in highly seismic areas. The profiles have been designed with two or three front ribs and one deep rib on the lateral flanges, to limit the phenomenon of local instability, notwithstanding the limited thickness of the sheet metal, producing in a total 16 or 20 bends that are without equal on the market of heavy industrial racks. The holes at a distance of 52mm have been carefully studied to render the profiles completely interchangeable, guaranteeing maximum compatibility of all the uprights with the different beams of the system and facilitating the assembly phases of the structure. The uprights can be painted or profiled using Sendzimir galvanized sheet metal.

The frame is made up of a structure using traverses and diagonals bolted to the uprights. Modulblok uses two different types of profiled elements for the frame, on the basis of envisioned load level: “C” profiles arranged according to a back-to-back configuration that recent research has demonstrated to be the most suitable to limit the deformation of the frame and avoid dangerous twisting effects in the uprights; for the heavier loads, profiled tubes that are crimped and stamped at their ends with a completely innovative design, created to improve the performance of the element with high-compression loads that may be stronger for applications in seismic areas. The profiles for the structures are made with Sendzimir galvanised sheet metal.

The beams are made up of two “C” profiles in cold-shaped steel, welded together and equipped with pressed connector hooks in highly-resistant sheet metal welded to the matching profile ends. The surface protection is guaranteed by powder coating.

Modulblok fittings

The connectors have been studied in their every minimum detail to guarantee a perfect match between the beam and upright to limit the movement of the connectors to minimum levels. Its unique and original design represents the real strong point of the Modulblok system, through the special positioning of the hooks at the corner of the connectors, which produces and excellent relation between resistance and rigidity, being ideal to favor the deformation of the connector without damaging the upright. This aspect assumes primary importance for applications in seismic areas, where it is necessary to localize deformations and the plastic hinges near the ends of the beams, without damaging the upright, as may be often found in structures with common frontal connections.

Base plates

The shelving is fixed to the floor using stamped base plates in galvanized structural steel, bolted to the uprights of the support structure so as to avoid looseness between the bolts and their holes, and then attached to the floor using ETA certified mechanical expansion bolts. In case of stronger stresses, special base plats made of welded and painted elements are used, which are bolted to the floor using chemical or mechanical anchor bolts.

Vertical and horizontal bracings

Warehouse structures, in specific cases, may be further reinforced using specially-designed rods to stabilize and brace the structure against actions produced by horizontal forces acting in a longitudinal direction parallel to the operation aisle. The Modulblok system used in seismic areas envisions the use of bracing elements that are carefully studied in their every detail, so as to develop adequate overall ductile characteristics in the system, without interfering when loading and unloading, they are located behind the shelves instead of in front. LOADING SHELVES For storage of loose bulk merchandise continuous shelves may be produced with galvanized sheet metal elements or shelves with a series of welded mesh holes or special elements that are compatible with fire-resistant priorities, walkways to access the shelves using textured slats or holes or continuous surfaces in corrugated steel and wooden panels.

Safety accessories

To increase the safe use of the shelving, Modulblok recommends the use of devices to avoid local and general damage to the support structures, and protective elements to reduce the risk of merchandise falling from the racks. In particular, the vast range of Modulblok accessories includes: - Back stop devices to hold the loading units and avoid the fall of any unit load positioned on the rack; - Frontal protection and shielding to protect the uprights from accidental bumps of forklifts, thus reducing the risk of damage to the structure; -Panels in welded mesh to prevent the accidental fall of packaged merchandise; - Load Warning Notices that clearly indicate the limits of rack use, identify the maximum load applicable for each type of beam used and the overall load applicable to the bay.

For several years now, Modulblok has been at the forefront of research and design of earthquake-resistant racks and warehouses.

Modulblok has always placed advanced research and high-level structural design at the centre of its activities, with the aim of developing innovative products in compliance with the strictest and most advanced quality standards.
In recent years, there have been an increasing number of collaborations with prestigious universities in the light of new regulations prescribing a series of tests to evaluate the mechanical properties of thin steel profiles.

Modulblok does not limit its research activities to what is prescribed by regulations, but anticipates the possible future design practices, with particular regard to safety of racks in seismic areas. To this end, our Company actively participates in the working groups of the Italian standardization (UNI) and, at European level, within the  “EUROPEAN RACKING FEDERATION” (ERF) and acting the “TECHNICAL COMMITTEE TC 344″ of the “COMITÉ EUROPÉEN DE NORMALISATION” (CEN), for the definition of technical standards for future design. Furthermore, our Company contributes to the European project “Seisracks2“, currently the most important research project in the world on the behavior of racks in seismic areas.

Collaboration with the Griffith University of Brisbane

This activity was born from the Company’s will to explore the behavior of frames subjected to high lateral loads (seismic action or wind), getting a more accurate estimate of actual rigidity compared to that provided by the stiffness test of frames required by EN 15512.
This research has led to the collaboration with Professor Gilbert from the Griffith University in Brisbane (Australia) who, with his staff, is considered one of the worlwide leading specialists in the field of cold-formed profiles and racks.
This collaboration has resulted in an important comparison between the shear test conducted according to the two approaches, the one provided by EN15512-2009 and an alternative one proposed by the Australian Standard AS4084-2012.
Modulblok has provided a substantial amount of prototypes to be tested in the laboratory of the “Centre for Infrastructures Engineering and Management” of the Griffith University.

– 36 Modulblok frames tested using 2 different structural configurations, 2 types of diagonals and three shapes of uprights.
– 13 tests on frames carried out according to the procedure laid down by EN15512-2009
– 23 tests carried out according to the alternative proposed by AS4084-2012

The comparison shows that the two methods are not equivalent and lead to different values ​​of transverse shear stiffness. The value derived from the alternative test is generally higher than the one obtained according to the EN15512 test: 1.2 to 2.0 times higher.
This research has led to a scientific paper published in the Journal of Constructional Steel Research (B.P. Gilbert, Kim J.R. Rasmussen, N. Baldassino, T. Cudini, L. Rovere “Determining the transverse shear stiffness of steel storage rack upright frames”, Journal of Constructional Steel Research 78 (2012) 107- 116), which highlights the insufficiencies of the test included in the European standard and shows the higher reliability of the alternative test of the Australian standard, with particular reference to the application of test results to freestanding structures and racks in a seismic area.
Today, thanks to Modulblok’s contribution, there is the concrete possibility of including this test in the European standard EN 15512 currently under review.

Future European Seismic Hazard

The high exposure of European countries and citizens to earthquakes  is highlighted also by the recent remapping of Seismic Hazard in Europe obtained by the SHARE project (Seismic Hazard Harmonization in Europe) funded by European Commission in the 7th Framework Programme. According to this remapping, the seismic hazard is now considered significantly higher not only in the south and east, but also in central and north Europe regions with moderate to high seismicity areas also in Countries like Belgium, Germany, France, Austria. In such regions, in which seismic risk was considered low since few years ago, civil structures including storage racks were obviously designed to withstand mainly static loads without any regard to the earthquake action, and nowadays are thus exposed to high seismic risks.