Effect of Brick Aggregate Content on Performance of Recycled Construction-Solid-Waste Aggregate

Area of Science:

• Civil Engineering
• Materials Science
• Environmental Engineering

Background:

• Road construction heavily relies on natural aggregates, leading to resource depletion and environmental strain.
• Construction solid waste, primarily concrete and brick slag, offers a sustainable alternative aggregate source.
• The presence of brick slag can negatively impact the performance of mixed recycled aggregates, limiting their application.

Purpose of the Study:

• To evaluate the suitability of recycled construction-solid-waste aggregate containing brick slag for road subgrade applications.
• To determine the effect of varying brick aggregate content on the California bearing ratio (CBR) and crushing value.
• To analyze the field compaction quality of mixed recycled aggregates.

Main Methods:

• Laboratory testing of mixed recycled aggregates with different brick slag proportions.
• Evaluation of California bearing ratio (CBR) and crushing value.
• Field compaction analysis using a 22 t road roller.

Main Results:

• Mixed recycled aggregates (9.5-19 mm) experienced significant crushing during compaction.
• Brick aggregate content below 40% demonstrated minimal impact on the performance of the recycled aggregate.
• Optimal field compaction involves a 22 t roller, five passes, and specific vibration patterns at 3 km/h.

Conclusions:

• Recycled construction-solid-waste aggregate with up to 40% brick slag is applicable in road subgrade layers.
• Controlled compaction is crucial for achieving desired performance with recycled aggregates.
• This study supports the environmental and resource-saving benefits of utilizing construction solid waste in road engineering.