The influence of nano-CaO and nano-Al2O3 and curing conditions on perlite based geopolymer concrete produced by the one-part mixing method

Abstract

• Perlite-based geopolymer can be produced by one-part mixture method. • Nano-CaO affects the strength of perlite-based geopolymer concrete negatively. • Nano-Al 2 O 3 affects the strength of perlite-based geopolymer concrete positively. • Nano-additives were more effective in reducing the volume of macropores formed in geopolymer concrete. In terms of sustainability, alternative binders have been sought despite the environmental effects of CO 2 gas released as a result of cement production. In accordance with this purpose, geopolymer binders produced by activating aluminosilicate materials with alkalis are one of these alternatives. This study aimed to produce one-part geopolymer concrete from aluminosilicate-based perlite, which is rich in SiO 2, and to improve its mechanical properties by adding nanomaterials. The effect of using nano-Al 2 O 3 and nano-CaO at 1 %, 2 %, and 3 % by weight instead of perlite on the properties of geopolymer concrete under different curing conditions (heat + ambient and heat + water curing) was investigated with SEM (scanning electron microscope), XRD (X-ray Diffraction), t -Plot/BJH (specific surface area and pore size distribution) and FT-IR (Fourier Transform Infrared Spectroscopy) tests, the compressive strength, flexural strength, length change. As a result, the applicability of the one-part mixture method in the production of perlite-based geopolymer concrete has been determined. Nano-Al 2 O 3 was found to be effective in perlite-based geopolymer concrete in terms of compressive strength and the optimum curing condition was heat + ambient curing. The addition of nanomaterials especially prevented crack and pore formation and according to t -Plot/BJH analysis, were more effective in lowering the number of macropores generated in geopolymer concrete, but increased the number of micropores. Moreover, the nanoparticles had no discernible effect on the geopolymerization process of perlite-based geopolymer concrete.