Maximization of fly ash in the manufacture of reinforced concrete pipe

Fly ash produced as a by-product of coal combustion in electric power plants is used in many commercial processes. The quantity of fly ash available, however, continues to outweigh its commercial applications. Current practice commonly specifies replacement of up to 25% of the required cement with Class C fly ash in the manufacture of reinforced concrete pipe (RCP). RCP sections with higher percentages of Class C or Class F fly ash were manufactured using the "packerhead method" and were subjected to external load crushing strength tests using the three-edge bearing test method. Results indicate that RCP manufactured with 40% Class F fly ash and up to 65% Class C fly ash meet ASTM C 76M external crushing strength standards for Class I-III RCP.