Effect of Ternary Cementitious System on Microstructure and Strength Behaviors of Concrete

Abstract

The effect of two local pozzolan, fly ash (FA) and metakaolin (MK) on the performance of the ternary system concrete was reported in this paper, particularly on modification of microstructure and strength properties. Different performances of individual material proved to benefit the other’s weakness. Additional FA improved workability and provided more uniform microstructure while MK strongly increased early age strength. The combination yielded the better performance of fresh and hardened concrete. The MK/FA ratio significantly affected compressive and flexural strength. Some forms of unstable compounds were found during 7-28 days of the modified mixtures, their effects were still unclear. The denser microstructures of ternary system also significantly improve the abrasion resistance. Weight loss appeared to reduce about half of the control. The proper ratio of MK and FA (10:10) appeared to have strong combination effects on workability improvement, slump loss as well as providing marked and continuous effect on long term strength.