Experimental study on mechanical properties of coal gangue base geopolymer recycled aggregate concrete reinforced by steel fiber and nano-Al₂O₃

Abstract Using recycled aggregates to prepare geopolymer concrete plays an essential role in reducing dependence on natural resources and solving the problem of waste accumulation. However, application aggregate (GRC) has been greatly limited due defects quality limitations brittleness materials. Therefore, work is dedicated improving GRC properties exploring mechanism action steel fiber (SF) nano-Al 2 O 3 . In this study, calcined gangue, slag, fly ash, were used as raw materials, influence SFs (0–1.25 vol%) was first explored by single factor analysis, basis, effect (NA) (0–2 wt%) GPC performance SF studied. The microstructure analyzed scanning electron microscopy. test results showed that adding could significantly improve splitting tensile flexural strength GRC, among which 0.75 vol% most excellent. increase compressive be more apparent. addition NA can make up for lack performance. When content 1 wt%, version Adding 1% significant advance analysis promote polymerization reaction, generate gel, contact interface between matrix compact, thus GRC.