Sustainable Infrastructure: Recycled Concrete Aggregates for Cycle Paths

Area of Science:

• Civil Engineering
• Materials Science
• Sustainable Construction

Background:

• Recycled concrete aggregates (RCAs) are increasingly utilized in construction.
• RCA properties vary significantly based on origin and processing.
• Previous research has not specifically addressed RCAs for Central European cycle path substructures.

Purpose of the Study:

• To evaluate the suitability of RCAs from diverse sources for cycle path substructure layers in Central Europe.
• To determine the mechanical and durability properties of concrete utilizing these RCAs.
• To establish guidelines for the appropriate use of RCAs in this specific application.

Main Methods:

• RCAs were sourced from airport, road overpass, and building demolition sites.
• Aggregate testing was conducted following European standards.
• Concrete mixtures were prepared using RCAs, and their compressive strength, density, water absorption, and frost resistance were evaluated.
• Specific cement classes (CEM II B/V 32.5) and water/cement (W/C) ratios were investigated.

Main Results:

• RCA concrete exhibited 28-day compressive strengths ranging from 5.9 to 17.3 MPa.
• Frost resistance ratios were consistently close to 1.0.
• Specific W/C ratios were identified to meet EN 12390-3 (C8/10 class) and D-04.05.01v02 standards.
• Concrete parameters indicate potential for RCA application with appropriate mix design.

Conclusions:

• RCAs from various origins are viable for cycle path substructure layers in Central Europe.
• Careful selection of cement type and W/C ratio is essential for achieving desired performance.
• Testing RCA properties is critical due to inherent variability to ensure quality and compliance.