Strength properties and durability aspects of sintered-fly-ash lightweight aggregate concrete
N. Divyah, R. Thenmozhi, M. Neelamegam
Abstract
The effect of basalt fibre on concrete made with sintered-fly-ash aggregates as coarse aggregates, a by-product of the processing of fly ash is studied in detail with respect to its strength, durability and cost effectiveness and compared with normal aggregate concrete. Four different mixes were developed for the M25, M30 and M40 grades of concrete with 0.25 % of basalt fibre in each mix. The rebound hammer test, ultrasonic pulse velocity, compressive strength, split tensile strength, flexural strength, Young's modulus, sorptivity and ponding test were investigated and a stress-strain curve was plotted. A linear-regression analysis was carried out to find the relationship between the mechanical properties of the concrete. A cost analysis worked to find the cost effectives of using the sintered-fly-ash aggregate. The findings indicated that the addition of basalt fibre showed a marginal increase in the compressive strength and a substantial increase in the split tensile strength and flexural strength was observed. The Young's modulus of the sintered-fly-ash aggregate concrete was low when compared with the conventional mix. The sorptivity test and the ponding test revealed that the sintered-fly-ash aggregate concrete showed a considerable decrease in durability. The outcome of the cost analysis showed that the use of sintered-fly-ash aggregate concrete reduced the cost by 12 % when compared with conventional route. The experimental test results throw light on the use of sintered-fly-ash aggreagte in concrete and basalt fibre proves the effectiveness of the lightweight concrete developed.