Unifying strength in precast concrete structures

335 columns, 446 beams, 255 TT floors and 18 floor slabs for DSV campus in Venlo

On Malcom McLeanstraat in Sevenum, construction is underway on the new cross-divisional campus of DSV, a global provider of transportation and logistics services. The campus includes a 19,000 m2 cross-dock with 128 docks and a two-level warehouse of over 34,000 m2, complemented by over 8,000 m2 mezzanine and 33 docks. Over 7,000 m2 of office space will also be provided. The warehouse has a height of 27 meters. On the floor will be a large shipping deck for trucks, accessible by a ramp. Whereas the floor will be built in steel, the construction of the first floor will consist of precast concrete. And the ramp and shipping deck are also constructed in precast concrete. To raise the technical quality, planning and manufacturability of the concrete structures to the highest level, the engineering firm Lincon BV, concrete manufacturer Holcon BV and installation partner Mammoet Montage joined forces.

Lincon BV, Holcon BV and Mammoet Montage can fall back on a long-standing and very close partnership, particularly in civil engineering and utility construction. The companies fully understand and trust each other and can switch quickly, which benefits both the execution and the end result. The precast concrete construction for DSV in Venlo is a wonderful calling card for this and was commissioned by Unibouw BV. "The campus for DSV is the first project we realize for this contractor," says Bert Peddemors, project coordinator at Holcon BV. "We were approached at a very early project stage, in collaboration with Lincon BV and Mammoet Montage, to convert the structural design of iKAABEE into a precast structure. An assignment we were awarded in part because of an impressive joint reference, namely the engineering, production and assembly of over 22,000 m3 of precast concrete elements for ctPark Amsterdam Cityhub. Moreover, a nice detail is that our sister companies Bisoton (concrete facade elements) and Hardeman | van Harten (facade cladding) are also involved in the DSV project."

Close construction team

The aesthetic design for DSV's BREEAM-NL certified new building was created by in-house architect AK83 and Palazzo. "In a close-knit construction team with Unibouw BV, Holcon BV and Mammoet Montage, we further developed Palazzo's aesthetic design and iKAABEE's structural design into a technically feasible and makeable design," says Mathijs van den Hurk, project manager at Lincon BV, an engineering firm with roots in the world of concrete and concrete structures. "In doing so, we carefully reviewed all critical components. Based on the wishes and requirements of the building user, main contractor, installers, concrete producer and concrete assembly specialist, we took care of the complete detail engineering. We also translated the basic main 3D model into clear and efficient production and assembly drawings." 

Precast concrete construction

Although the structural design of iKAABEE tended toward precast, it had not yet been carried out fully in accordance with the precast idea, says Van den Hurk. "We changed this and cut the construction into elements that are excellent to produce, transport, hoist and assemble. Thanks to our extensive structural knowledge and expertise and by bridging the gap between all relevant stakeholders, quality and feasibility come together perfectly." As an example, he mentions the tall columns that had to be worked with. "To ensure proper and fast assembly at 14 meters, we focused, among other things, on the easiest possible connections. Moreover, additional reinforcement was added in some places so that temporary support stamps could be avoided here."

Special facilities

During the preparatory phase, Mammoet Montage contributed ideas on the correct construction logistics, construction sequence and phasing. "Based on the capacity of our crawler cranes, the maximum weight of the elements was determined," says Nico Put, sales manager at Mammoet Montage, one of the specialist divisions within Mammoet Nederland B.V. "The various construction flows were also coordinated. Both with Unibouw BV and with Reijrink Staalconstructie b.v., which realized the steel structure for the floor. And the crane tracks were also conceived in advance." The project for DSV had three crane tracks, he says. "The construction crane always drove over the concrete bases, on which the columns were placed at a later stage. To make this possible, the cuttings reinforcement for the connections had to be omitted. Instead, anchors (inserts) were poured into the bases, where the plug reinforcement was screwed in at a later stage." 

'Best for project'

The maximum weights created challenges in some places, Van den Hurk says. "For example, regarding the beams of the loading deck. Heavy guys that we pinched slightly in dimensions so that they could also be included in the assembly flow." In particular, the dimensions of the elements were determined in agreement with Holcon BV. Peddemors: "Moreover, the maximum loads were important.   

For example, of the shipping deck and ramp, which have to absorb serious forces. For the warehouse and mezzanine floors, we focused particularly on efficiency and durability. For example, our prestressing tracks offered the possibility of still making the desired spans with less concrete and less traditional reinforcement." Van den Hurk: "This is how we worked as a trinity toward a 'best for project' solution."

Substantial numbers

In October 2022, Holcon BV started production of the precast concrete elements. "At our production site in Xanten, 335 columns, 446 beams, 255 TT floors, 18 floor slabs and some walls were produced," Peddemors says. "The concrete elements were temporarily stored in our bag field and transported just-in-time to the construction site. A total of 1,018 trips were required to transport all the elements, which included heavy transport." In particular, the beams for the docks had hefty dimensions and weights, he says. "The heaviest beam weighed a whopping 68.2 tons! This beam was transported from Xanten to Venlo and assembled in early June."

Quick and efficient assembly

On February 28, 2023, Mammoet Montage started precast concrete assembly. "From our facility in Etten-Leur, we assembled all precast concrete elements in two construction streams and with two assembly crews," says Put. "In addition to the aforementioned elements from Holcon BV, we processed approximately 2,500 channel plates in just 18 weeks! For this we used a 300-ton and 180-ton crawler crane, among others."

 The foundation piles for the warehouse had already been poured on site by Unibouw BV, he says. "We put the precast columns on top of these, followed by the precast beams and hollow-core slabs." The work for the docks was similar, only here TT slabs were used. "This is also where the heaviest beams were installed," he says.

Whereas the heaviest beam in front of the docks weighed 68.2 tons, the beams had a weight of about 30 tons, Put says. "The columns weighed about 15 tons. To set these columns in their vertical position, we laid concrete-legoblocks in the field. Combined with three heavy braces, the stability of the columns was ensured during the assembly work." To tilt the approximately 13-meter-long columns, Mammoet Montage had a special tilt frame made into which the columns could be placed and tilted using a single crane. The final elements were assembled at the end of July.