Development of Polycarboxylate Ether-Based Fly-Ash Sand and Its Potential Application as a Construction Material

Abstract

Due to increasing growth in the construction sector, demand for good quality natural river sand (NRS) is huge. This prompts extensive riverbed mining, which poses severe environmental consequences. This research aims to replace the natural river sand with polycarboxylate ether-based fly-ash sand (PFS) developed by mixing high volumes of fly ash with a commercially available high-solid-content polycarboxylate superplasticizer (HS-PCE). The physical, mechanical, and chemical properties were evaluated against the requirements of Indian standards and found in compliance. The developed PFS belonged to Zone I. It exhibited a good frictional angle (43°) and a specific gravity of 2.23. However, the water absorption and pH were higher for PFS in contrast to NRS. Durability tests like soundness and alkali-aggregate reactivity for PFS exhibited results within the prescribed limits per the Indian standards provision. Finally, the performance of PFS in the mortar was evaluated by casting cube specimens. The cubes with PFS achieved 26.12 MPa at 28 days, which was 96.85% in contrast to the strength of control concrete with NRS. The findings of this study indicate that PFS can act as a sustainable alternative to conventional NRS for construction works because it not only provides a similar mortar performance but also focuses on utilizing fly ash on a bulk scale.