After 30 years of wear and tear on a concrete slot storage barn, PacifiCorp was faced with a facility in serious need of quick repair. To accomplish the task, PacifiCorp, which owns and operates the Huntington Canyon Plant, asked Furmanite, a worldwide technical and engineering services company, to get the job done within a very short time. The project had to be completed when coal deliveries to the barn could be minimized, allowing the concrete slot storage to be worked on in sections.

Call to Action
After years of providing leak sealing, machining, and valve repair services to PacifiCorp and then winning the competitive bid, Furmanite was called on to repair the 30-year-old concrete slot storage coal barn at PacifiCorp’s Utah facility. The coal barn serves as a multi-day storage facility and rudimentary fuel blending facility. The barn is about 450 feet long and has a roof over the slot storage reclaim area. A rotary plow pulls the coal from the barn onto a conveyor for transport to the power plant. The coal is dropped from above the slot storage with a conveyor belt moving tripper suspended beneath the barn roof.

The challenge Furmanite faced was repairing severe damage to the concrete slopes and slot openings to the rotary plow in the bottom of the barn slot, which was caused by large track dozers hitting the sides of the structure while pushing into and out of the barn.

“The damage to the PacifiCorp coal barn was even more severe than originally anticipated or inspected,” said Tim Coughlin, Furmanite’s Concrete Services Specialist who oversaw the project. “And, the job was especially challenging because the work had to be completed during the one month period when coal deliveries were suspended for planned mining maintenance.”

The coal barn was originally designed to allow the coal to slide down the steep side slopes to the slot above the rotary plow feeder and conveyor area. However, the original concrete slumped and created a “shelf” at the bottom of the slope, instead of a continuous 50 degree slope which would allow the coal to slide freely. This prevented the coal from sliding and caused it to rest on a ledge at the slot. Significant sagging of the side slope areas caused the joints to open, allowing water to seep behind the concrete, causing wash outs and rusting of the reinforcing steel. As a result, the concrete was significantly cracked and falling apart.

Solution
Working within the one-month deadline, Furmanite quickly developed and implemented a concrete solution. This included placing the most experienced concrete services specialists on the job and using the most effective concrete materials, which would allow the project to be completed within the allotted time. Furmanite is not affiliated with any OEM suppliers, allowing customers to choose the most optimum solutions and a variety of repair products.

“We relied on Furmanite’s experience, understanding the required project timeline and our desired results to provide us with the best materials at the lowest price,” said Thomas Roberts, the PacifiCorp-assigned Project Engineer.

Furmanite concrete specialists began by cutting and removing the damaged concrete. The next step entailed replacing the old reinforcing steel with new steel. New concrete was then formed and poured.

The second phase of Furmanite’s solution required a specialist to apply a coating on the bottom 10 feet. Furmanite selected a fast-setting concrete that would cure and hydrate quickly. The bottom 10 feet was then coated with an abrasive-resistant durable coating. This process created a very slick area at the lower portion of the hopper, allowing the coal to slide easily.

Results
When originally bidding the project, PacifiCorp and Furmanite estimated the quantity of work, realizing that it could change because only a small portion of the barn slot was available for evaluation prior to the work. The actual project increased nine-fold due to unforeseen damage to the concrete. Furmanite met the challenge by quickly increasing its work force at the plant and obtaining the necessary materials in order to meet the deadline.

As a result, the PacifiCorp project was completed approximately two days ahead of schedule. Furmanite’s concrete solution created a process which was faster and more efficient and, as demonstrated at PacifiCorp, ultimately can lead to a plant’s increase in production and operation.