Flyash: Coal byproduct put to good use

Southern Company is turning a byproduct of expended coal into a versatile building material. The byproduct - flyash - is mixed into flowable fill, a concrete-like material that can be used as fill or backfill material around pipe trenches, bridge abutments, underground storage tanks and in other locations where it would be difficult to deposit compact soil or crushed stone.

"Flowable fill pours easily from conventional ready-mix trucks with minimal effort," said Lamar Larrimore, principal engineer for SCS research and environmental affairs. "It self-levels, hardens and develops strength on its own without using compaction equipment.

"In addition, depending on the project, it can be designed to remain in place permanently or to be excavated, which is easy when using small equipment, even hand tools," Larrimore added.

Flowable fill is made of cement, sand, water and flyash, which is produced at power plants during the combustion of coal. Using flyash in flowable fill is an environmentally friendly alternative to disposing of it.

Southern Company aggressively markets flyash and often participates in developing new applications for it. Already, several plants sell a large quantity of flyash each year for use in ready-mix concrete.To promote flowable fill, Southern Company recently helped organize and host a seminar and demonstration of the product in Birmingham for members of the construction industry as well as representatives from municipal, county and state organizations. Many of the concrete manufacturers that attended expressed an interest in producing flowable fill.

"While this isn`t a new product, it hasn`t received much exposure in the Southeast," said Dean Dodgen, Southern Company`s manager of coal-combustion products. "The seminar and demonstration were one part of an overall system effort to market coal-ash materials."

Contact Dean Dodgen at 404-506-7755 for more information on how to make flyash work for you.