Repairing an aggregate bin on a concrete plant is not fun but a necessary part of maintenance and repair. The wear and tear of an aggregate bin can be attributed to many causes including the impact of material, rain/snow, and wet materials. Over time the combination of these factors will literally dissolve the walls and supporting structure of a concrete plants aggregate bins and batchers. Making aggregate bin inspections and patching part of a 6 month or annual maintenance program will add many years to your plant and save you thousands of dollars in major bin repairs and lost time as your plants ages.
Deterioration of aggregate bins and batchers on concrete plants is such a major concern that many companies choose to use specialty products such as urethane liners and thick A/R steel to combat the effects of aging and wear on these massive steal structures. For companies that don’t have a regular aggregate bin inspection and repair policy in place the addition of urethane bin liners or hardened steel liners is a suitable way of extending the life of aggregate bins and batchers, but the cost of materials and installation is significant. It is also important to add these aggregate bin wear liners while the bins are still in good condition or the cost of materials and installation will be significantly greater because when deterioration of the aggregate bin or batcher is too great the loos of quality steel makes it difficult to weld the new materials in place, and the addition of more substructure steel and strapping may be necessary to properly secure the wear liners in place.
Proactive concrete plant owners and operators willing to implement a 6 month or annual maintenance and repair program on their aggregate bins and batchers at able to identify problem and high wear areas quickly and add patches of steel to reinforce those areas before the areas around the area also become compromised. The benefit of this strategy is that repair patches will typically be smaller and the time to repair will be less because there should be quality steel that the patch can attach to. When problem areas are left too long the steel around the area will eventually become unweldable requiring the use of additional reinforcement and patchwork.
How does the regular inspection work? At a designated time period (six months, year, etc.) the aggregate bins are completely emptied the interior and exterior walls of the bins are inspected visually. Upon visual inspection it is usually evident the areas of highest impact and decay. Once those areas are identified, cut a steel plate of suitable thickness several feet larger than the problem area and weld in place over the problem area. It is important to remember to completely weld the plate in place. Tack welds or incomplete welds will eventually fail and likely block the material flow through the gates requiring the material to be emptied from the bin by hand to retrieve the fallen plate. While it is common to see plates bolted in place in an aggregate bin or batcher, this practice is also discouraged. In manufacturing, bolts are rarely used in aggregate bins and batchers, however when they are they are normally flat tipped and countersunk into the steel to create a flush surface. Bolts that are not countersunk will eventually ultimately sheer off from the flow of material over the head again releasing the plate to fall to the bottom of the batcher. The use of non-counter sunk grade 5 bolts is suitable for a short term solution, but it is important to use grade 5 or better bolts and to make the appropriate repairs as soon as possible.
Some aggregate bins can be challenging to enter and even harder to bring heavy materials such as steel plates into for the repair, but having a strategy to enter the bins and a regular inspection process usually allows materials of smaller sizes (more manageable) to be used. Still, depending on the configuration of your batch plant, you may need a tele-handler (Lull), man lift, multiple extension ladders and other equipment to properly conduct the inspection. Multiple man crews should be used for this process and someone should always be present outside of the structure to respond to any potential emergency inside of the aggregate bins. It is also important to never enter aggregate bins during operation, and all bins should be emptied before entering an aggregate bin to reduce risk associated with interior wall collapse.
In closing, the difficult process of inspecting and repairing concrete plant aggregate bins can be a several hour project and certainly wouldn’t be considered easy; it is far less expensive and easier to complete an inspection and preform small repairs as needed than allowing your equipment to decay for years without repair.
Do you have concrete aggregate bins in need of repair? FESCO Direct offers onsite services to safely inspect and repair aggregate bins, conveyors and other equipment used at concrete batch plants. Our repairs are commonly made with high quality urethane liners or A/R steel, however we can use your material of choice and accommodate almost any budget.
Call us to discuss the specifics of your project at (800) 880-7350.