Modified Fine Recycled Concrete Aggregates with a Crystallizing Agent as Standard Sand Replacement in Mortar

Area of Science:

• Construction Materials Science
• Sustainable Engineering
• Civil Engineering

Background:

• Standard sand in mortar production presents sustainability challenges.
• Recycled fine aggregates offer a potential alternative for eco-friendly construction materials.

Purpose of the Study:

• To evaluate mortar performance using recycled fine aggregates from concrete waste.
• To assess the impact of crystallizing agents on mortar properties.

Main Methods:

• Mortars were prepared with 25% to 100% recycled fine aggregate substitution.
• Particle size distribution of recycled aggregates mimicked standard sand.
• Mechanical properties and durability were assessed.
• Crystallizing agents were incorporated into specific mortar series.

Main Results:

• Recycled concrete sand significantly improved mechanical properties compared to standard sand.
• Mortars with up to 100% recycled aggregate showed enhanced compressive strength.
• Higher superplasticizer dosages were required for high substitution rates.
• Crystallizing agents increased flexural strength in certain conditions but not compressive strength.

Conclusions:

• Recycled fine concrete aggregates are technically feasible for high-performance mortar production.
• Substitution with recycled aggregates offers enhanced mechanical properties.
• Crystallizing agents show limited benefits for compressive strength but can improve flexural strength.