Possibility of producing high-strength fine-grained concrete without cement

Abstract

This paper has shown the potential of manufacturing of high-strength fine-grained concrete without cement from industrial wastes in Vietnam. In which, fly ash "Phả Lại" and blast furnace slag "Hoa Phat" are used as alumino-silicate materials, NaOH 12 M and Na₂SiO₃ solutions are used as the alkali-activator solution. The ratio between the activator solution and the alumino-silicate material is 0.32. The content of FA/GBFS was surveyed at 60/40, 50/50, and 40/60, respectively. The workability of the concrete mixture is determined by the flow of a truncated cone and the strength of the test specimen is determined on a prismatic mold with dimensions of 40x40x160 mm. The objectives of the research are to make a fine-grained concrete mix with the spread from 15 to 20 cm and compressive strength at the age of 28 days reaching over 70 MPa.