ZSM-5 waste from volatile organic compounds processing as a supplementary cementitious material

Abstract

ZSM-5 waste, the spent product of ZSM-5, has a high content of active SiO2, and thus, it can be potentially used as a supplementary cementitious material (SCM) in cement. In this paper, standard mortars with 5, 7, and 10% of cement replacement were prepared, and the compressive strength and fluidity were tested. The characterization techniques included: X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), hydration heat liberation, and Thermal gravimetric (TG). Results demonstrate that the addition of ZSM-5 waste can improve the strength, decrease the fluidity of cement mortar, and reduce the hydration heat of cement. Cement paste with the addition of ZSM-5 waste shows a lower amount of portlandite due to the pozzolanic reaction. Besides, the microstructure of reaction products exhibits a more condensed structure.