Abstract:
Current work summarizes research done on potential of sintered
fly ash lightweight aggregate based concrete and its suitability
as an aggregate. The manuscript presents physical and chemical
parameters of ingredients such as fly ash as well as binders
adopted in manufacturing process covering effect of these
materials on parameters related to pelletization like duration,
angle of inclination and rotation speed and its subsequent
effect of aggregate characteristics. The impact of sintering
temperature and its duration on aggregate characteristics is also
discussed. The physio-chemical and mechanical characteristics
of sintered fly ash aggregate is briefly presented. The review of
literature suggests that specific gravity and water absorption
of sintered fly ash lightweight aggregate is low and high
respectively as compared to conventional aggregate. The use of
additives such as alkaline activators, styrene-butadiene rubber,
quick lime etc. and additional treatments such as coating or
vacuum impregnation has shown potential for reducing water
absorption. The mechanical performance of sintered fly ash
lightweight aggregate in concrete is different from normal
concrete. Factors affecting compressive strength, flexural
strength and modulus of elasticity apart from the characteristics
of manufactured sintered fly ash lightweight aggregate are
cement content, supplementary cementitious materials,
additives used, treatment done to aggregate, aggregate
content, shape index of aggregate etc. Studies have indicated
no direct relationship between factors affecting concrete
durability such as water absorption, mechanical perfromance,
cement content, water penetrability and freeze-thaw resistance
of sintered fly ash lightweight concrete.