Source
Journal of Engineering Research, v. 20, no. 1, p. 33-44.
English abstract
The use of fly ash in construction
has been on the rise, yet its application in
pavement construction remains relatively
underexplored. This study addresses this gap by
critically reviewing 70 years of research on fly ash
usage in pavement engineering, offering valuable
recommendations. Class 'C' fly ash is employed
for soil stabilization, while class 'F' is used in
concrete. In both flexible (asphalt) and rigid
(concrete) pavements, fly ash primarily functions
as a filler material. Fine ash, owing to its fineness,
enhances asphalt concrete by reducing void ratios
and water sensitivity, as well as easing subgrade
compaction while increasing compressive
strength. Incorporating fly ash into Hot Mix
Asphalt (HMA) enhances resistance to cracking
and oxidative ageing. Adding fly ash (up to 25%)
significantly boosts soil failure stress and strain
values by 106% and 50%, respectively, while a
combination of 8% lime and 18% fly ash yields
maximum shear strength. A modest amount of
lime (1-2%) mixed with 10% fly ash achieves a
maximum dry density of 1.98 gm/cm3 at an
optimal water content of 12.62%. Additional
testing by researchers corroborates and validates
the findings of this literature review.
