What is an additional benefit of using fly ash in concrete aside from increasing strength?

Using fly ash in concrete provides several benefits beyond just increasing strength, one of which is reducing costs. Fly ash is a byproduct of coal combustion in power plants and can be used as a partial replacement for portland cement in concrete mixtures. Since fly ash is often less expensive than cement, incorporating it into concrete can significantly lower material costs for construction projects.

Additionally, by reusing fly ash, which would otherwise be disposed of in landfills, the environmental impact of concrete production is reduced, aligning with sustainable construction practices and further enhancing cost-effectiveness. This dual benefit not only makes concrete more economically viable but also supports recycling initiatives.

The other benefits provided in the options, though valuable, do not directly relate to the cost aspect. While fly ash can indeed enhance the workability of concrete and minimize shrinkage, these factors do not inherently contribute to lowering the overall cost of the concrete mix in the way that using a less expensive material does.