Company: Hoffmann Construction, out of Muscatine, Iowa has been in business for 100 years.
Jobsite: Edgar, Nebraska. Foreman: Brandon Ziegenhorn
Hoffmann Construction was contracted to create a 58 foot diameter grain silo with 38 degree sloping, cone-shaped base that was 34 feet from bottom to top of slope.
80 yards of concrete were used to complete the pour. The reason for pouring a 38 degree conical base for a silo is two-fold.
Over the years, OSHA (Occupational Safety and Health Administration), has had to deal with people getting trapped and suffocating in silos when they have gone in to clean them out.
In order to reduce the chances of somebody dying during the cleaning of these bins, a new silo design was needed. Above ground, self-feeding steel bins have been around for a number of years,
38° Conical Grain Silo Base
however, concrete silos with a base poured steep enough for grain to flow is another matter. It had been determined that 38 degrees is the ideal angle for grain to flow freely.
Placing concrete on a 38 degree slope is a challenge because the concrete also wants to flow to the bottom. Therefore, the concrete has to be poured very stiff (around a 2 slump) just to keep it from sliding down the sloped sides.
The Lura Lightning Strike Roller Screed is uniquely suited for this type of challenging job.
The first challenge was the fact that the silo is 34 feet from bottom to top. One 34 foot tube would be difficult to transport, but with the patented coupling system Lura developed, the 34 feet was a matter of connecting a 20 foot, 12 foot, and a 2 foot tube together to span the distance. All tubes can be transported on a ladder rack of a pickup truck.
The second challenge was having a pivot at the bottom of the cone that could adapt to any slope grade. Again, Lura’s patented center-pin pivot was a perfect fit for the job.
At the end of the day, Brandon Ziegenhorn said he doesn’t know how else he would have been able to pour this without the innovation the Lightning Strike Roller Screed had to offer.