Municipal Solid Waste Incineration (MSWI) Ashes as Construction Materials-A Review

Area of Science:

• Environmental Engineering
• Materials Science
• Waste Management

Background:

• Extensive research exists on municipal solid waste incineration (MSWI) ashes for recycling.
• Despite research, MSWI ash recycling programs remain limited globally, particularly in the U.S.
• Construction materials offer a promising avenue for MSWI ash reuse due to high consumption and lenient criteria.

Purpose of the Study:

• To comprehensively review MSWI ashes for use as construction materials.
• To compare MSWI ash management practices between Europe and the U.S.
• To evaluate engineering and environmental properties of MSWI ashes in construction applications.

Main Methods:

• Literature review of MSWI ash management practices.
• Analysis of engineering properties and performance data for ash-based construction materials.
• Assessment of environmental properties and criteria for MSWI ash utilization.

Main Results:

• Asphalt and concrete applications show significant promise for MSWI ash reuse based on mechanical and leachate properties.
• High absorption of MSWI ash necessitates increased asphalt binder content in hot-mix asphalt.
• Metallic elements in ash can generate H2 gas in concrete's high-pH environment.

Conclusions:

• MSWI ash utilization in asphalt and concrete is viable with proper material characterization.
• Pre-treatment and modified mix proportions can mitigate challenges associated with MSWI ash use.
• Effective management and recycling of MSWI ashes can be enhanced through construction material applications.