2.3 Construction and Demolition Waste
Approximately 48 Mt of waste (excluding fly ash) was generated within Australia in 2010–11. This equates to about 2.2 tonnes per capita, of which 60% was recycled or recovered for embodied energy. The overall resource recovery rate in Australia increased by 9% (from 51% up to 60%), between 2006–07 and 2010–11. This equates to the percentage of waste that is either recycled or recovered for energy. The Australian Capital Territory (ACT) had the highest resource recovery rate (79%) followed by South Australia (SA) (77%), New South Wales (NSW) (65%) and Victoria (62%).
Australian levels of municipal waste recovery were comparable to those in the US, Finland, Italy and the United Kingdom, but considerably lower than many northern and western European nations, as well as Korea (Blue Environment Pty Ltd & Randall Environmental Consulting 2014; Austroads 2014). The rates of waste generation, recycling and recovery, by jurisdiction, in 2010–11 in terms of kg/capita are provided in Austroads (2014). The rates of waste generation and recycling recovery by waste category (in terms of tonnage) are also presented. It was noted that a large proportion of this waste presently going to landfill has the potential to be reprocessed as aggregates for reuse.
According to Austroads (2014), from a C&D recycling industry perspective, national uniformity is encouraged in terms of:
- Site development and licence conditions: each state and territory has a different policy in-relation to the requirements for the development of infrastructure for the recycling and resource recovery industry. The streamlining of the industry at a national level would make it simpler for organisations to expand across borders; it would also reduce the need for different corporate policies within each jurisdiction.
- Product standards and common terminology: businesses that operate in different jurisdictions often have difficulty transferring process standards and intellectual property across borders. This is mainly due to different regulation requirements in each jurisdiction. Additionally, there are different requirements for materials within the same jurisdiction, particularly within local government. The recent development and national acceptance of the Transport Infrastructure Product Evaluation Scheme (TIPES) should assist in the acceptance of qualified products and the standardisation of practices (Austroads 2014).
Extensive use of recycled materials in road pavement construction in Western Australia was encouraged by the Australian Geomechanics Society (Cocks et al. 2017). These recycled materials include: crushed concrete, comingled demolition material, crushed vitrified clay pipe, crushed glass, scrap rubber, asphalt millings and plastic.
More details on the economics of materials availability and recycling is provided in Case Study 1.
The work reported in Austroads (2014) undertook to determine the economic costs associated with the decreasing availability of traditional road-building materials and the extent to which the future availability of pavement materials impacts on road maintenance and construction activities.
Based on a review of the existing literature and observed experience across the industry, this work addressed:
- the status of national quarried and recycled materials, product development and challenges across the C&D recycling industry, including products and markets for recycled products and some barriers and opportunities for the uptake of recycled materials
- the current disposal costs, the number of recycling facilities, the materials processed and products and markets in New South Wales, Queensland, Victoria, Western Australia and South Australia
- the reuse of recycled crushed glass (RCG)
- industry employment associated with recycled pavement materials.
A survey was conducted aimed at identifying existing initiatives/strategies at the national/state or local level that address the use of local and recycled pavement materials and their in situ performance. The survey included environmental managers, road construction industry stakeholders and members of the Austroads Assets Task Force (ATF) and the (then) Austroads Pavement Technology Review Panel (PTRP).
Relevant industry stakeholders were also surveyed requesting information relating to the future demand for pavement materials, and indications of whether quarries had reached their finite life. The survey found that there were differences between state road agencies in terms of the reporting of the quantities of pavement materials used in different applications – both quarried and recycled. A possible reason for this was that construction works undertaken by contractors and information on usage may not be reported regularly. The results also indicated that, while seeking sustainable materials has become a subject most government agencies were keen to promote, the practical use of recycled materials remained limited.
In order to determine the economic costs associated with the decreasing availability of traditional road-building materials and the extent to which future pavement materials availability will impact on road maintenance and construction activities, an assessment of the estimated financial impacts of incorporating recycled aggregates into pavement bases was undertaken. It was found that there was insufficient data to complete a suitable economic analysis. As a result, information from VicRoads was used to determine the financial cost savings of incorporating recycled aggregates into pavement bases (see Table 2.1).
This financial analysis was undertaken by allowing the addition of up to 15% recycled component per annum within pavement constructions Victoria-wide. It was found that there was an annual saving of approximately $24 million or a 4% reduction in the total cost of pavement materials (see Table 2.2). In terms of the current level of resource recovery and use in Victoria, recycled materials can only realistically supply approximately 10–20% of the market's need for crushed rock and aggregates. After taking into consideration a cheaper supply price ex-bin, their lower density (meaning less quantity of materials are required to cover a given area), and resulting lower freight costs, the cost of the recycled component of an in-place pavement could be in the order of 25–30% cheaper. However, this is not necessarily the case in all markets.
In addition to the survey and financial analysis, two case studies were conducted from Fairfield City Council (NSW), representative of local government, and ResourceCo (SA), representative of industry. For Fairfield City Council, the cost savings achieved by the use of these recycled materials compared to quarry materials for equivalent pavement performance, the proportion of waste materials diverted from landfill, and production and consumption of recycled materials, were documented. ResourceCo (2017) provided qualitative information relating to their recycling facilities.
The use of recycled materials, and the maturity of the industry, varies around Australia. A key issue impacting on this project, and warranting the need for further work, was data availability. Specifically, the amount of data with respect to the availability of traditional road-building materials and future demand for pavement materials was extremely limited.
Notwithstanding these limitations, there are significant benefits associated with the incorporation of recycled aggregates in pavement bases, and Fairfield City Council is an example of this successes. Additionally, a number of environmental benefits could be achieved, including reduced quarrying, the conservation of finite resources for future generations, reduced landfilling, energy consumption and subsequent reductions in greenhouse gas (GHG) emissions and impacts on climate change
|Materials||Class 1||Class 2||Class 3||Class 4|
|Quarry materials||$26–$28/tonne ex-bin||$24–$26/tonne ex-bin||$22–$24/tonne ex-bin||$16–$22/tonne ex-bin depending on source type|
|Recycled materials (Melbourne)||$20–$22/tonne ex-bin||$18–$20/tonne ex-bin||$14–$16/tonne ex-bin|
Source: Graeme Newman, Technical Services, VicRoads (e-mail communication April 2014).
|Material price and quantity||Annual estimates – base and subbase applications||Total|
|100% quarry product||Zero recycling|
|Aggregates placed (million m3)||11|
|Price $/m3 (placed)||$58|
|Total cost $m||$638|
|85% quarry product||15% recycled aggregate|
|Aggregates placed (million m3)||9.5||1.5|
|Price $/m3 (placed)||$58||$42|
|Total cost $m||$551||$63||$614|
|Overall financial savings $m||$24|
Source: RM Consulting Group (2014).