Curing is an important process in the creation of concrete. Properly cured concrete will meet strength requirements; exhibit volume stability; and resist freezing and thawing cycles, abrasion, and scaling.
Turbostream is a curing solution by Finland-based Polarmatic. “Turbostream uses steam, which adds moisture into the mix, and a gas burner for warming the mix,” says Stuart Galloway, President, Canadian Concrete Expo. “The added moisture makes Turbostream ideal for dry-cast products, such as drainage piping, manholes, and other underground infrastructure, because the producers of pre-cast products need the concrete to stay moist longer.”
With Turbosteam, combustion gas is combined with steam to provide a carbon dioxide-rich, moist heating medium. “Because Turbosteam circulates carbon dioxide within the curing chambers, it also results in increased initial strength of the concrete and therefore allows faster curing times,” says Galloway.
FIRST CANADIAN TURBOSTREAM CUSTOMER
M Con Pipe & Products Inc. (M Con) is a precast concrete facility in Ayr, Ontario. The facility features nine 70-ton silos and 20,000 square feet of production floor space that uses steam curing.
M Con became the first in Canada to employ Turbostream technology when they purchased Polarmatic’s Turbomatic-1500 in 2013. At the time, the company was looking to upgrade their aggregate heating capabilities, Polarmatic and M Con found the perfect solution. “We had looked at other solutions for aggregate heating, but the cost and capabilities made much more sense for us to go with Polarmatic,” says Steve Galloway (no relation), Plant Superintendent, M Con. “With the Polarmatic, we can use it not just for aggregate heating, but also curing, hot mixing water for batching and to heat the buildings on site.”
At the time of the purchase, M Con had two functioning steam curing machines that each had life expectancies of several more years.
“When we installed the Turbomatic, we took our two curing systems offline,” says Steve. “The Turbostream is efficient enough that it has no problem meeting our demands of curing and heating aggregates and our buildings for less owning and operating costs than having to purchase multiple systems manufactured by others to achieve the same results.”
Steve says, with a natural gas heating system, there have been no issues at all with carbon monoxide present at any time. “I know that the presence of carbon monoxide can be a concern for producers who use steam curing machines, but there have been zero carbon monoxide issues in the six years that we have had the system.”
Steve says the blower inside the Turbomatic system has the power to penetrate the aggregates very deep. In extreme winter conditions, when the frozen aggregates delivered from the aggregate pit, it will freeze to our steel bin surge hopper instantly and need to melt the dump truck size load of aggregates in order to convey them into our holding hoppers inside the facility.
“Our previous system was inefficient,” says Steve. “When heating aggregate for 12 minutes on a day where the temperature is -30oC, the entire load wouldn’t be heated enough. We would get bridging of the aggregate and staff would have to break it up to get it up the conveyor. Now, the aggregate gets thoroughly heated within three minutes with no worries.”
1. This blog is courtesy of the Canadian Concrete Expo, Toronto, Jan. 22-23, 2020. For more, visit: https://canadianconcreteexpo.com/.