Role of High-Volume Mineral Admixtures on Characteristics of Engineered Cementitious Composites
Adeyemi Adesina and Sreekanta Das
Appears on pages(s):
drying shrinkage; engineered cementitious composites (ECCs); fly ash (FA); ground calcium carbonate (GCC); permeability; slag.
In this study, mineral admixtures were used to substitute a high volume of portland cement (PC) in engineered cementitious composites (ECCs), and the corresponding permeability properties and drying shrinkage were evaluated. Six ECC mixtures were made with high-volume mineral admixtures (MAs) (that is, MA/PC ratio of 5) alongside a control ECC mixture (that is, MA/PC of 2.2). The findings from this study revealed that the application of a higher content of MAs ensued in a rise in the permeability of the ECCs at early ages. However, the permeability properties of the ECCs were significantly reduced in the long term, resulting in similar or lower permeability compared to that of the ECCs made with a
lower amount of MA (that is, 2.2). The 28-day water absorption of ECC made with blast-furnace slag (BFS) as the MA at an MA/PC of 5 is 5.4%, while that of the control ECC with an MA/PC of 2.2 is 5.1%. The outcome of this research also revealed that the application of ground calcium carbonate (GCC) is beneficial in reducing the drying shrinkage of the ECCs. The drying shrinkage at 32 days of ECC made with GCC at an MA/PC of 5 is 14.3% and 60% lower than when fly ash (FA) and BFS were used at the same MA/PC (that is, 5). However, GCC should be used in ECCs as a filler rather than an MA as there was a significant increase in the permeability of ECCs made with only GCC as the MA. Nonetheless, FA or BFS can be used alongside GCC to reduce the detrimental impact of GCC on the permeability characteristics of the ECCs.