Application of the Hazardous Waste Vitreous Enamel Generated in the Production Process of Heating Devices as a Partial Replacement for Cement

Abstract

Solving problems with hazardous waste materials is of crucial importance today. In the presented study, the application of waste vitreous enamel as a cement replacement up to 30% in mortar and concrete production was investigated. The chemical and physical-chemical characterization of the starting material was performed, as well as a leaching test and physical-mechanical characterization of mortar and concrete mixes. Obtained results showed that, due to its chemical composition, the vitreous enamel used must be classified as hazardous waste. At the same time, it possesses pozzolanic properties and satisfies minimal criteria for use as a cement replacement. Testing mortars and concrete mixes indicate that waste vitreous enamel can be applied as a construction material for cement replacement in the maximal amount of 20%. The leaching test was performed in accordance with international standard EN 12457-2 on hardened mortar with a maximal cement replacement of 20%. The results showed that there was no significant release of toxic elements, i.e., that the practical application of hazardous waste vitreous enamel in the construction industry may be fully in line with environmental standards.

Possibility of Using Vitreous Enamel Waste in the Construction Industry as the Concept of Cleaner Production

“…With the increasing concrete age, a small decline in compressive strength was observed with an increase in the percentage of cement replacement by waste materials. The authors [17,58,59] in the study of the properties of concrete with the addition of recycled glass and waste vitreous enamel had comparable inferences.…”

“…This does not match with the fact that in the cement hydration process, the pozzolanic reaction occurs later and after the formation of Portland (calcium-hydroxide), which is necessary for its initiation. The hydration products shrank due to the pozzolanic reaction, which caused increased shrinkage of the mortars with waste enamels added [58][59][60]. The quality of cement composites primarily depends on mechanical strengths, especially compressive strength.…”