Performance of structural lightweight concrete produced by utilizing high volume of fly ash cenosphere and sintered fly ash aggregate with silica fume

Abstract

The increased productivity of fly ash, a waste from the power plants, and the reduced availability of natural aggregates are severe threats to our environment's sustainability. The strategic utilization of this waste to fulfil the need of the construction industry can solve these problems. This paper aims to evaluate the performance of structural lightweight concrete (LWC) produced by utilizing high volumes of fly ash cenosphere (FAC) and sintered fly ash aggregate (SFA), obtained from fly ash, with silica fume (SF). Natural aggregates were partially/fully replaced by FAC and SFA. Similarly, cement was partly replaced by SF. Total seventeen concrete mixes were prepared with different combination of FAC (75% &100%), SFA (75% & 100%) and SF (10%, 12% & 15%) inclusive of one control mix. The mechanical, physical and non-destructive properties of these concrete mixes were evaluated to satisfy the specified criteria of the structural LWC. The environmental soundness of these concrete was also studied. The above-mentioned properties of these concrete reduced drastically by using FAC and SFA, while the same enhanced with the inclusion of SF and reduction of water-binder ratio by adding superplasticizer. These concrete mixes were also satisfying the criteria of structural LWC and enhanced the environmental soundness. These mixes can be recommended for the production of structural LWC utilizing high volume of industrial waste and preserving cement and natural resources, which, in turn, reduces the environmental impacts and minimizes the solid waste disposal problems to achieve the sustainability in the concrete production.

Keywords

• tructural lightweight concrete
• Fly ash cenosphere
• Sintered fly ash aggregate
• Silica fume
• Mechanical properties
• Physical properties