Performance study and environmental evaluation of alkali-activated materials based on waste photovoltaic glass

Abstract

To alleviate the problems of energy shortage and environmental pollution, 15 alkali-activated materials (AAM) were designed and prepared based on slag and waste photovoltaic glass powder (WPGP). The setting time, fluidity, compressive strength, drying shrinkage rate and mass loss rate of AAM were tested. The effects of Na2O content, the modulus of water glass and the mass ratio of slag to WPGP (S/W) on the above properties were discussed. The properties and microstructure of AAM were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). The economic and environmental benefits of AAM were evaluated using a simplified method. The compressive strength prediction model of AAM under different curing time was established. The results show that the effects of Na2O content and the modulus of water glass on the properties of AAM are complementary. The maximum compressive strength at 28 d can reach 75.3 MPa. The predicted value of compressive strength is in good agreement with the test value, indicating that the established model has a high accuracy. The more encouraging result is that compared with traditional Portland cement, AAM shows significant environmental friendliness. The energy consumption and CO2 emission of 1 m3 AAM were 20.06%-42.45% and 49.01%-71.79% lower than those of the same volume Portland cement respectively. The above results show that the developed AAM can be used as a promising cementitious material to replace Portland cement.