COMPRESSIVE STRENGTH, FLOWABILITY, AND ULTRASONIC PULSE VELOCITY TESTS OF PORTLAND CEMENT-FLY ASH-CALCINED CLAY MORTARS

The cement production process significantly affects the environment and contributes to air pollution. Consequently, there is a growing emphasis on employing alternative materials or minimizing cement usage as a solution to address environmental issues and reduce air pollution. In this investigation, an examination was conducted by substituting Portland cement with a weight of 50% with both fly ash and calcined clay. The findings revealed that replacing Portland cement with fly ash resulted in a decrease in compression strength. However, concurrently incorporating calcined clay increased compressive strength. Higher compressive strength compared to the 50% Fly ash mix was achieved by adding 20 wt.% Metakaolin and 20 wt.% Calcined clay Lopburi due to their finer particle size. As a result, the pozzolanic reaction is better than Lampang calcine clay (30FA20CClam). Additionally, ultrasonic pulse velocity testing indicated that higher values in the specimen correlated with increased compressive strength.