Bridge Engineering Center

About the research

This project was triggered by interest in sustainable development and new environmental regulations on waste disposal. The addition of supplementary cementitious materials (SCMs) such as fly ash, slag, and other industrial byproducts to cements can improve concrete workability, durability, and long-term strength, but a gap in knowledge about the performance of SCM concrete under a variety of conditions has limited its use by the PCC paving industry. In this project, correlations were found among the source and proportion of the SCMs, curing conditions, concrete set time, maturity, strength development, and cracking potential.

Other findings include the following:

• Concrete performance varies with the source and proportion of cementitious materials used.
• As SCM content increases, longer curing times or higher curing temperatures may be needed.
• SCM concrete can perform comparably to or better than ordinary portland cement concrete under hot weather conditions.
• Traffic opening time of pavement should be based on strength and time-temperature factor.
• Potential benefits of a more informed use of SCM concrete include improved concrete workability, lower risk of thermal cracking, improved concrete durability and long-term strength, and reduced overall concrete cost.