Cement-treated pavement layers incorporating construction and demolition waste and coconut fibres: a review

ABSTRACT

This review deals with the use of waste materials in cement-bound granular mixtures (CBGM) to be applied as base or sub-base layers in road pavements. The construction of road pavements demands significant quantities of natural resources, and currently, despite the increasing environmental concerns, the use of recycled materials in CBGM is minimal. Such large-scale applications would allow crucial savings in the extraction of non-renewable natural materials and promote the consumption of waste materials that otherwise would be discarded in landfills. Several waste materials have a high potential to be used for CBGM construction. This review focuses mainly on using recycled aggregates, clay ceramic from brick and tile waste, and coconut fibre obtained from coconut coir’s waste. The recycled aggregates, derived from construction and demolition waste, can replace, partially or totally, the natural aggregates. The stabilising agent, typically Portland cement, can be partially replaced by the active fraction of the recycled aggregate, as the adhered mortar may contain not hydrated cement, and clay brick waste that has a potential for pozzolanic activity. The coconut fibre can be added for a fibre-reinforcement effect, potentially improving durability and mechanical properties.

KEYWORDS:

• Cement bound granular mixture
• hydraulically bound mixture
• construction and demolition waste
• recycled aggregate
• clay brick waste
• cement replacement
• coconut fibre
• fibre reinforcement

Acknowledgements

The authors wish to acknowledge the funding received from the Portuguese national funding agency for science, research and technology (FCT – Fundação para a Ciência e a Tecnologia, I.P.), under the Research Project PTDC/ECI-TRA/32244/2017.

Disclosure statement

No potential conflict of interest was reported by the author(s).