Editor’s note: International Cement Review ran the article below in its April 2024 issue:
Continental Cement Company, a Summit Materials company, has built another DomeSilo with Dome Technology, this time at its Davenport, Iowa, USA facility. This DomeSilo marks the third collaboration between the companies, both of which are powerhouses in their own industries.
The DomeSilo can store 125,000 short tons of cement powder, and according to Dome Technology’s records, the structure is among the largest-capacity cement storage facilities in the world, said sales manager Lane Roberts.
The dome size is a response to demand that’s been building for the past decade. Continental Cement (CCC) Davenport facility battled limited cement-storage capacity for many years, resulting in cement being loaded on barges and stored on the river during winter months. But this wasn’t a sustainable plan; with cement and barge demurrage costs increasing each year, Summit Materials and Continental Cement commissioned this transformational dome project to invest in larger, more permanent storage.
“CCC’s Davenport Plant was able to reduce its demurrage costs for cement storage on the river and eliminate the need to curtail production. This project positions us well to meet customer commitments and ensure adequate supply coming out of the winter months into the busy spring and summer seasons,” Continental Cement Co. plant manager Brett Imsland said.
The facility, then and now
The Davenport facility produces cement from minerals mined at a nearby quarry. Product is stored on site temporarily, then shipped by barge to customers.
Multiple existing concrete silos are still utilized for cement storage before product moves via airslide into the dome. The DomeSilo is 165 feet in diameter and 171.5 feet tall. An FLS Ful-Floor™ pneumatic reclaim system mobilizes product; the floor is faceted with slopes in four directions, moving cement to a single tunnel that is 18 feet wide and 12 feet tall. Cement is reclaimed at 350 stph and pneumatically conveyed to barges on the Mississippi River.
The area below the DomeSilo was unconfirmed fill, and to ensure a proper foundation, the site was mass excavated to bedrock and backfilled with structural backfill. The new DomeSilo is directly adjacent to the existing concrete silos, and additional care had to be taken to ensure the existing silo foundations were not underpinned during the mass excavation. This took a collaborative design effort between Dome Technology and Continental Cement.
Collaboration was key in every element at Davenport. According to Roberts, CCC provided valuable direction on how the dome would be used operationally, and FLSmidth developed a customized, economical reclaim solution based on their input and project needs. Dome Technology’s role was to take CCC’s operational goals and combine these with solutions on the project to produce a seamless dome facility.
In collaboration with CCC, Dome Technology helped provide technical solutions beyond the DomeSilo construction, including construction of the large reclaim tunnel and installation of the FLS Full-Floor reclaim system and aeration piping.
Dome Technology’s scope of work also included construction of a mechanical/electrical building and demolition of three bays in an existing building to clear way for the DomeSilo and the new mechanical/electrical building.
Dome storage benefits
Storage is often one of the largest components in any new facility, and a dome is built with an unlimited lifespan — its concrete shell and geometry boast unrivaled strength. Dome construction methods require no interior trusses, so the entire inside volume can be utilized for storage or reclaim systems.
All domes provide ideal conditions for stored materials requiring a controlled environment. Seamless concrete construction, coupled with a fabric membrane surrounding the entire dome, prevents water and moisture from seeping in. The dome’s insulated nature reduces heating and cooling of the walls and air inside, preventing condensation from forming on the interior and extending the life of the concrete structure.
A dome’s strength and geometry also provide a tolerance for some differential settlement. Those qualities combined with geotechnical engineering and site analysis ensure proper foundation selection and performance.
Domes for cement storage
The most common dome model for cement storage is the DomeSilo, a structure that’s taller than it is wide and allows companies to stack product deeper on a smaller footprint, requiring less property at the site. The increased capacity is made possible by geometry: The double curvature of a dome lends itself to the ability to build up, rather than out, and the curve provides strength at all points of the structure, even at the apex. The entire interior can be used to contain product.
In recent years Dome Technology introduced a second type of DomeSilo: the Drive-Through DomeSilo that allows companies to fill truck or rail directly from the storage structure and speed up the process of product reception to delivery. The Drive-Thru delivers 100 percent live reclaim from a fully aerated floor. Product flows through a hopper for loading into truck and/or rail. An in-line lump crusher on the loadout stack-up ensures that lumps passed through the receiving system do not make it into trucks.
In 2018, a Drive-Thru DomeSilo was built at a recently acquired Continental Cement site in Memphis. While the existing silo and adjacent scale had not been used for some time, complete upgrades of these assets along with a new barge unloader, dock upgrades and Drive-Thru DomeSilo has allowed Continental Cement to become the leader in service in the Memphis market.
The benefits of teaming up again
Partnering on repeat projects benefits all the players involved — the evidence is clear in this third robust project borne of CCC and Dome Technology collaboration.
“It’s a strong indication of trust. In a way, it’s kind of like a marriage relationship; you get to know what the other partner is like and it’s easier to talk through differences and resolve problems that will inevitably come up,” Roberts said. “They know us, and we know how they think and feel, and we can better match our skill set to their needs the more we work with them.”