Performance Testing and Evaluation of Double-Layer Pervious Concrete Based on Recycled Aggregates

Area of Science:

• Civil Engineering
• Materials Science
• Environmental Engineering

Background:

• Ecological slope protection faces challenges in water management and material sustainability.
• Construction waste recycling offers a potential solution for sustainable building materials.
• Pervious concrete shows promise for hydraulic and ecological applications.

Purpose of the Study:

• To develop and evaluate a double-layer pervious concrete composite structure using recycled fine aggregates for enhanced ecological slope protection.
• To determine optimal mix design parameters for both single-layer and double-layer pervious concrete incorporating recycled fine aggregates.
• To validate the performance of the developed composite structure through field tests on slope protection.

Main Methods:

• Single-factor experiments were conducted to assess the impact of recycled fine aggregate replacement ratios and water-cement ratios on single-layer pervious concrete properties.
• Parametric studies on double-layer composite concrete focused on optimizing the paste-to-coarse aggregate ratio.
• Field tests were performed on slope protection sites to evaluate the performance of the double-layer pervious concrete configuration.

Main Results:

• An optimal water-cement ratio of 0.36 and a 45% recycled fine aggregate replacement ratio were identified for single-layer pervious concrete, balancing permeability and compressive strength.
• A paste-to-coarse aggregate ratio of 0.45 was found to be optimal for the double-layer composite, achieving a balance between compressive strength and permeability.
• Field tests confirmed superior water retention in the planting layer and effective infiltration attenuation by the fine particle layer, with interlayer capillary action ensuring moisture redistribution.

Conclusions:

• The developed double-layer pervious concrete composite structure effectively utilizes recycled fine aggregates for sustainable ecological slope protection.
• The optimized mix design provides a theoretical framework and experimental validation for balancing hydraulic and mechanical performance in pervious concrete.
• The study demonstrates the potential of this composite structure to improve water management and moisture distribution in soil strata for ecological engineering applications.