Reusing Discarded Ballast Waste in Ecological Cements

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction

Background:

• Ordinary Portland Cement (OPC) production is energy-intensive and contributes to CO2 emissions.
• Pozzolanic materials enhance concrete properties and reduce cement content.
• Construction and Demolition Waste (C&DW) represents a significant waste stream with potential for reuse.

Purpose of the Study:

• To investigate the feasibility of using discarded ballast from C&DW as a pozzolanic material in cement.
• To characterize the properties of C&DW ballast and its performance when substituted for cement.
• To evaluate the production of pozzolanic cements with improved characteristics.

Main Methods:

• Characterization of C&DW ballast using chemical, mineralogical, and morphological analyses.
• Mechanical testing of cementitious materials including compressive and flexural strength.
• Substitution of cement with C&DW ballast at 10% and 20% by mass.

Main Results:

• The discarded ballast exhibited pozzolanic properties suitable for cement modification.
• Cements produced with 10% and 20% C&DW ballast substitution met the criteria for type II or IV pozzolanic cements.
• Satisfactory mechanical test results were obtained for the modified cements.

Conclusions:

• Reusing C&DW ballast as a pozzolanic material is a viable strategy for sustainable cement production.
• The use of C&DW ballast can lead to the development of eco-friendly cements with desirable properties.
• This approach contributes to waste valorization and reduces the environmental impact of the construction industry.