Evaluation of the tridymite formation as a technique for enhancing geopolymer binders based on glass waste


Dadsetan S., Siad H., Lachemi M., ŞAHMARAN M.

JOURNAL OF CLEANER PRODUCTION, cilt.278, 2021 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 278
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.jclepro.2020.123983
  • Dergi Adı: JOURNAL OF CLEANER PRODUCTION

Özet

The low solubility of glass powder is one of the important elements hindering the large volume recycling of glass waste (GW) in structural geopolymer materials. The current study aims to investigate an enhancement process of GW to be reused in improved performance geopolymer binders. The method relies on the devitrification of GW powder through heat treatment at below and above the transition temperature of quartz in order to develop new phases of tridymite formation. The devitrified glass waste (DGW) was incorporated in optimized combinations with metakaolin using an algorithmic mixture design approach of pre-targeted ratios of SiO2/Al2O3, Na2O/SiO2 and liquid/solid. Mixtures of raw GW and metakaolin were used as control geopolymers. Mechanical strengths of the developed binders were assessed up to 90 days of ambient curing. In addition to the X-ray diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR) used to characterize the formation of tridymite in DGW powder, comprehensive analysis, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and FTIR, was completed to inspect the microstructural change based on oxide ratios and DGWcontents. Sustainability analysis was also performed to assess the energy consumption and CO2 emission of the produced geopolymer binders. The results indicated that the maximum tridymite formation occurred under 1-h heating at a temperature of 900 degrees C. The existence of higher tridymite content caused a significant increase in the compressive strengths of geopolymers made of 75% DGW compared to control mixtures with raw GW. The creation of more silanol (Si-OH) groups and generation of accelerated and greater degree of geopolymerization were shown as the outcomes of DGW in the geopolymer reaction process of binders. (C) 2020 Elsevier Ltd. All rights reserved.