The project evaluated a class of organic compounds (diammonium salts of alkenyl dicarboxylic acids) as additives for concrete that may improve its durability against freezing and thawing and reinforcement corrosion. The material also reduces heavy metal leachate, potentially making environmentally acceptable the use of incinerator ash (both bottom and fly ash) in concrete.
Freeze-thaw, compression, and indirect tension tests were performed to determine the effectof additives on concrete properties. Porosity and permeability measurements also were done to determine their effectiveness in preventing access of chloride salt solution to the steel. Results showed a rather adverse effect of admixtures on concrete workability and strength. Also, the permeability was not significantly improved. However, the concrete showed excellent freeze-thaw resistance (Figure 1). Furthermore, leaching tests showed that the admixtures significantly decreased the leaching of lead from the concrete. The admixtures have potential to be effective air-entraining agents for concrete for improved freeze-thaw durability. No additional action is planned by NCHRP-IDEA. The final report is available from the National Technical Information Service (NTIS # PB96-147970).
The final report for this IDEA project can be found at:
https://www.trb.org/studies/idea/finalreports/highway/NCHRP013_Final_Report.pdf
