Alkali-activated metakaolin mortars using glass waste as fine aggregate: Mechanical and photocatalytic properties: Fid-Bau Portal

Alkali-activated metakaolin mortars using glass waste as fine aggregate: Mechanical and photocatalytic properties

Mejía de Gutiérrez, Ruby / Villaquirán-Caicedo, Mónica A. / Guzmán-Aponte, Luis A.

Highlights • Alkali-activated mortars based on metakaolin and TiO2 particles were evaluated. • Glass bottle waste was used as an alternative fine aggregate. • The compressive strength was 31.5 MPa at 28 days of curing. • The thermal conductivity of the mortars 100G10Ti was 0.87 W/m.K. • The self-cleaning photocatalytic capacity of these mortars was increased 72.4%

Abstract In the present study, properties such as density, absorption, porosity, compressive strength, thermal conductivity and photocatalytic activity of alkali-activated mortars based on metakaolin added with TiO2 particles were evaluated. TiO2 particles were incorporated in proportion of 10 wt%. Ground glass (GB) obtained from glass bottle waste was used as an alternative fine aggregate in proportion up to 100% as replacement of natural sand (S). The alkaline activator was a mix of potassium silicate and hydroxide. The photocatalytic activity was measured by the removal of Rhodamine B and the microstructure of the developed material was studied by scanning electron microscopy. The results obtained in this study reveal a reduction in the percentage of absorption of 16.3%, and porosity of 7% for mortars when S is replaced by GB. The mortar prepared with 100% GB reached a compressive strength of 31.5 MPa compared to 28.0 MPa for reference mortar (100% S). The thermal conductivity was reduced by approximately 25%. Finally, the self-cleaning photocatalytic capacity using GB as fine aggregate increased 72.4%. This type of cementitious materials contributes to mitigate environmental pollution and reduces the maintenance costs of structures.