The use of recycled materials has become accepted throughout the ready mixed concrete industry in response to an increasing environmental focus and the growing cost of disposing of waste material.
To assist with the continuation of this trend CCANZ has released Technical Report 14: Best Practice Guide for the Use of Recycled Aggregates and Materials in New Concrete – a resource for optimising the performance and engineering properties of recycled aggregate in concrete.
The key to recycling is to achieve a balance between economic pressures and ecologically sound practices.
Several market constraints and technical challenges exist when developing markets for secondary products. These include consumer uncertainty about the quality and consistency of products. In addition, there can be a lack of practical performance and engineering data on recycled materials.
Developing and adopting performance requirements specifically for secondary and recycled products will promote their specification, and also ensure that externally verified quality certification and compliance systems are adopted.
To this end, CCANZ in partnership with BRANZ and supported by the Aggregate & Quarry Association of New Zealand (AQA) has written Technical Report 14.
TR 14 outlines the processes involved in the use of recycled materials as aggregate in concrete and the effects of these materials on the fresh and hardened properties of concrete made from them.
It is intended to act as a resource to optimise the practical performance and engineering properties of recycled and secondary waste materials as aggregate in concrete supplied in accordance with NZS 3104:2003 Specification for Concrete Production, as well as act as the basis for future revisions of NZS 3104 and NZS 3121 Specification for Water and Aggregate for Concrete to potentially incorporate recycled materials.
TR 14 is also designed to raise awareness of the need for concrete recycling in New Zealand, and presents technical guidelines to specifiers, contractors, aggregate suppliers, and concrete manufacturers on the use of recycled aggregate in concrete, and on the recovery of concrete aggregate and fines from left over fresh concrete.
By providing a general overview of recycled concrete in construction, TR 14 will also be of interest to regulatory bodies offering information on the suitability of recycled material for use in construction projects.
TR 14: Best Practice Guide for the Use of Recycled Aggregates and Materials in New Concrete [download pdf]