Quantification of the properties of enzyme treated and untreated incinerator bottom ash waste used as road foundation

Abstract

A substantial amount of incinerator bottom ash (IBA) waste is generated annually from burning municipal solid waste. IBA is similar to aggregate consisting of ferric metals, non-ferrous metals, brick and tile fragments, ceramic, glass, stone, dirt, etc. In this work, IBA waste was mixed with conventional limestone aggregate in an attempt to achieve a blend with acceptable mechanical properties and minimum environmental risks for use in road foundation layers. Enzyme treatment was applied in order to improve the behaviour of IBA–limestone blends. A series of laboratory tests, such as cyclic triaxial compression tests, pH monitoring and scanning electron microscope, were adopted to determine the materials' mechanistic behaviour and microstructure characteristics. Emphasis was on examining the effect of various parameters, such as IBA content, enzyme content, moisture content and curing time. Results of this study showed that IBA blends gave a favourable performance as road foundation layers in comparison with the control limestone blend. Microstructure and chemical analysis results showed that the addition of plant-based enzyme improved the mechanical properties of the control limestone blend; however, it did not have any noticeable effect on the IBA blends.

Keywords:

• incinerator bottom ash
• enzyme
• triaxial test
• scanning electron microscope
• chemical analysis

Acknowledgements

The authors are indebted to Aggregate Industries for the technical and financial support of this study. The authors also extend their gratitude to the technical staff in Material Science, School of Engineering, for their assistance with the SEM and EDXS work. The award of a study scholarship by the Egyptian government to pursue this research programme is gratefully acknowledged.

Notes

1. Email: [email protected]

Additional information

Notes on contributors

Abdelkader Ahmed

1