Work

Mechanical and durability properties of M sand based hybrid fibre reinforced binary blended geopolymer concrete under ambient curing

Year: 2026

Type: article

Abstract: Concrete is the most widely used construction material after water; however, its strong dependence on ordinary Portland cement (OPC) leads to considerable environmental impacts. Geopolymer concrete (GPC), produced using industrial by-products such as fly ash and ground granulated blast furnace slag, has emerged as a more sustainable alternative. At the same time, the increasing depletion of river sand has encouraged the use of manufactured sand as a substitute fine aggregate. Despite these advantages, GPC often exhibits brittle behaviour, which can be effectively mitigated through fibre reinforcement. This study examines the mechanical and durability performance of binary blended geopolymer concrete incorporating fly ash and slag, manufactured sand, and 1% hybrid fibres under ambient curing conditions representative of field practice. Mixes were designed with a solution-to-binder ratio of 0.45, sodium hydroxide concentrations of 8 M and 10 M, and a NaOH-to-Na₂SiO₃ ratio of 2.5. The results show a moderate reduction in workability (36%), accompanied by a clear improvement in compressive strength (7.4%), while the measured elastic modulus closely agrees with analytical predictions. Durability performance was significantly enhanced, with notable reductions in sorptivity by 21.65% and chloride ingress by 36.48% compared with the control mix. Overall, the findings demonstrate that hybrid fibre-reinforced geopolymer concrete with manufactured sand offers improved durability and structural performance, highlighting its potential as a sustainable and high-performance alternative to conventional OPC concrete.

Source: Discover Sustainability

DOI: 10.1007/s43621-026-03128-6

Authors: H. M. Anil Kumar, B. Suguna Rao, Ranjith A., M. B. Sreenivasa, M. S. Shobha, B. O. Naveen