Strength development and microcosmic mechanism of waste glass powder cement mortar

Abstract In this article, the strength characteristics of the cement mortar with waste glass powder of different size and content at different ages were studied. The mechanism of strength development was analysed from the microstructure of mortar specimens based on scanning electron microscopy (SEM) and electronic dispersive spectroscopy (EDS). The results show that the compressive strength and flexural strength of the mortar specimens increase significantly with a higher age. There is an optimal content of glass powder corresponding to the maximum strength. The glass powder of smaller particle size clearly promotes the development of compressive strength and flexural strength in the mortar specimens. It is found from SEM-EDS that glass cement mortar has a larger amount of internal hydration products and higher density compared with ordinary cement mortar. The density of cement mortar incorporating 15 wt% glass powder increases gradually with the decrease of glass particle size. The hydration products and compactness of the cement mortar adding 200–500 mesh glass powder experience an increase and then a decrease with a rise in the glass content. The strength enhancement with the addition of glass powder are mainly attributed to the microaggregate filling effect and pozzolanic effect of the glass powder, as well as to changes in the interfacial transition zone.