Properties of Geopolymer Mixtures Incorporating Recycled Ceramic Fines

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction Materials

Background:

• Geopolymer matrices offer a sustainable alternative to traditional cement.
• Fly ash (FA) is a common precursor, but its availability and properties can vary.
• Recycled ceramic fines (CFs) present a potential supplementary or replacement material.

Purpose of the Study:

• To optimize geopolymer production by examining heat curing and fly ash replacement with ceramic fines.
• To determine the optimal percentage of ceramic fines (CFs) for fly ash (FA) replacement in geopolymer matrices.
• To evaluate the impact of curing temperature on the properties of geopolymer composites containing CFs.

Main Methods:

• Geopolymer mixes were prepared with varying percentages of ceramic fines (CFs) replacing fly ash (FA).
• Specimens were heat cured at different temperatures (65°C and 85°C).
• Laboratory tests assessed compressive strength, bending strength, bulk density, and water absorption. Microscopic analysis and porosity assessment were also conducted.

Main Results:

• Increasing curing temperature from 65°C to 85°C positively impacted geopolymer properties.
• Replacing 37.5% of fly ash (FA) with ceramic fines (CFs) enhanced physical and mechanical properties.
• Higher CF replacement levels led to increased porosity, consequently decreasing compressive strength, bending strength, and bulk density.

Conclusions:

• Optimal geopolymer performance is achieved with a curing temperature of 85°C and 37.5% fly ash (FA) replacement by ceramic fines (CFs).
• Excessive use of CFs beyond 37.5% negatively affects geopolymer properties due to increased porosity.
• The study highlights the potential of CFs as a partial replacement for FA in geopolymer production under optimized conditions.