COLUMBIA — Commuters heading toward MU from the south or west in the past week might have noticed a large white sheet on the south tower of the MU Power Plant. It's not a public art project — the sheet is actually a knitted polyethylene fabric intended to secure loose pieces of concrete on the 320-foot chimney.
Workers were operating from suspended scaffolding this week to secure the fabric to the tower with cables. The fabric will stay in place throughout the winter in advance of an estimated $3.8 million repair project scheduled to begin in the spring.
Campus Facilities Director Karlan Seville said that the fabric is a precaution and that nobody has been injured by falling concrete. “The netting is a prevention measure,” Seville said.
Assistant Vice Chancellor of Facilities Gary Ward said the damage was a result of the chimneys' age.
"They're old," Ward said, adding the damage is the natural result of repeated freezing and thawing. Moisture gets into cracks and expands as it freezes. The expansion causes pieces of concrete to chip off, a process known as spalling.
"Anytime you have a concrete structure there is the possibility of spalling," Ward said.
The two main chimneys were built in 1980 and 1981. This is the first time concrete maintenance has been performed since the towers were built.
Repairs to the chimneys will occur over the next two years. The project is in the design phase, after which Campus Facilities will solicit bids. Repairs on each chimney will take about six months to complete. Work on the south tower will begin in March 2010 and work on the north tower will begin in March 2011.
“The epoxy used on the chimney repair can only be used when it’s 55 degrees or warmer,” Seville said. For that reason, work can only be done during the warmer months.
The repairs will ultimately involve wrapping both towers in carbon fiber as well as applying epoxy to cracks in the concrete. In addition, the ladders and scaffolding on both towers will be replaced with galvanized steel. The new fixtures will be anchored with stainless steel in order to prevent the kind of rust stains that can currently be seen on the chimneys. Ward said the repairs will give the chimneys a "glossier look."
The temporary fabric will be installed on the south tower and only on the side that faces Stewart Road. The other areas where concrete could fall are contained within the enclosed grounds of the plant.
“It’s not an issue on the other side because everyone wears hard hats,” Seville said.
The MU Power Plant is one of two coal-burning plants in Columbia, the other being the Columbia Municipal Power Plant, 1501 Business Loop 70 E., operated by the Columbia Water and Light Department. The Columbia plant has one 300-foot chimney, also made of concrete.
Tad Johnson, the municipal plant's power production superintendent, estimates that chimney was built around 1976. He said it is inspected regularly and has not needed concrete repair.
The MU Power Plant provides all of the campus’ heating and cooling through a network of steam tunnels. It also provides two-thirds of the campus’ electricity needs in an average year. It is capable of providing all of the campus’ electricity needs but MU usually ends up buying a portion of its power from the grid during off-peak months when it’s cheaper to do so.
Seville said the plant will continue to operate at full capacity while the repair work is done.