Researchers at the University of Tokyo have found a way to combine waste concrete and captured carbon dioxide to create a usable form of concrete called calcium carbonate concrete.
A new recyclable material could revolutionise the construction industry, help disaster affected areas and be used in space exploration, according to a global research team headed by Monash University.
Researchers are leading the development of archimats – an emerging area of ‘architectured’ materials that have an organised intertwined or interlocked inner architecture.
“As a result, archimats have an extra degree of freedom expanding the design space that conventional composite materials, such as concrete, cannot possess,” a Monash University statement reads.
“Archimats can be engineered to have superior strength, enhanced ductility, a high tolerance to damage, good thermal insulation and sound absorption. They can also better absorb energy, as well as provide improved compliance and flexibility.”
One way to achieve this property profile, especially of metallic materials, is through severe plastic deformation (SPD) – a special metalworking technique that results in an ultrafine grain size or nanocrystalline structure.
“The structural patterns caused by SPD processing can improve the mechanical characteristics and physical properties of materials,” the statement reads.
Project lead Yuri Estrin, an Honorary Professorial Fellow in Monash University’s Department of Materials Science and Engineering, said a further benefit of archimats is the ease of assembly and disassembly it provides a structure, as well as the nearly full recyclability of the elements involved.
“Archimats therefore offer smarter, safer and more sustainable materials for use in manufacturing and industrial design, with the building industry being arguably the greatest potential beneficiary of this design concept,” Professor Estrin said.
“Archimats are also suitable for micro manufacturing. They can be produced using desktop or benchtop manufacturing processes, without the need for heavy equipment and large amounts of material.”
Professor Estrin said archimats could reduce the use of concrete in construction, thereby cutting carbon dioxide emissions associated with concrete production.
The material also has potential for rebuild use in arid or disaster-affected zones, including the creation of rapidly deployable and removable structures in danger areas, such as a town or city impacted by fire, for first responders and displaced citizens.
According to Professor Estrin, the material opens up new possibilities for industry to explore the use of archimats for application in smart manufacturing, in particular the development of gear for microelectromechanical systems, micro devices and miniaturised drones, as well as superior structural materials for the automotive and aerospace industries.
The European Space Agency is also considering the use of these architectured materials for the construction of a lunar base.
University of Queensland PhD candidate Danish Kazmi is developing a technique to transform glass waste into geotechnical columns and reduce the use of sand in the construction industry.
The geotechnical engineering student is investigating the use of crushed glass waste as an alternative to sand for ground improvement during construction works.
“Both sand and glass waste have a similar chemical composition, so we expect them to behave similarly when optimally used in geotechnical construction,” Mr Kazmi said.
“My research looks at the performance of glass waste within ground columns as an environmentally friendly alternative to sand columns, which are commonly used at the moment.”
Mr Kazmi said the columns are designed to strengthen the earth below a building and improve its load-bearing characteristics.
“Using glass waste in this way not only preserves precious sand resources and promotes closed-loop recycling, but could also reduce the carbon footprint of the construction industry by cutting down on the amount of sand that needed to be quarried,” Mr Kazmi said.
“I have always been passionate about helping to create circular economies.”
New research has found a way of turning biosolids from sewage into cheaper, higher performing bricks suitable for the construction industry.
A research team from RMIT University has developed a fired-clay brick as a sustainable solution for the wastewater treatment and brickmaking industries.
The bricks are made up of biosolids, a by-product of the wastewater treatment process, and were found to have a lower thermal conductivity than other bricks, meaning they will transfer less heat and potentially give buildings higher environmental performance.
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The research examined the physical, chemical and mechanical properties of fired-clay bricks incorporating different proportions of biosolids, from 10 to 25 per cent.
Researchers found brick firing energy demand was cut almost in half for bricks that incorporated 25 per cent biosolids, due to the organic content and could considerably reduce the carbon footprint of brick manufacturing companies.
Around five million tonnes of the biosolids in Australia, New Zealand, the EU, US and Canada currently go to landfill or stockpiles each year. By using a minimum of 15 per cent biosolids content in 15 per cent of the bricks produced, the research team estimates around five million tonnes could instead be used for construction.
The bricks have passed compressive strength tests and analysis demonstrated heavy metals are largely trapped within the brick. Biosolids can have significantly different chemical characteristics, so the researchers recommend further testing before large-scale production.
Lead investigator Associate Professor Abbas Mohajerani said the research sought to tackle two environmental issues – the stockpiles of biosolids and the excavation of soil required for brick production.
“More than 3 billion cubic metres of clay soil is dug up each year for the global brickmaking industry, to produce about 1.5 trillion bricks,” Mohajerani said.
“Using biosolids in bricks could be the solution to these big environmental challenges.
“It’s a practical and sustainable proposal for recycling the biosolids currently stockpiled or going to landfill around the globe,” he said.
The results of a comparative Life Cycle Assessment and an emissions study conducted as part of the research confirmed biosolids bricks offered a sustainable alternative approach to addressing the environmental impacts of biosolids management and brick manufacturing.
The research, funded by RMIT University, Melbourne Water and Australian Government Research Training Program scholarships, is published in the “Green Building Materials Special Issue” of Buildings.
Pictured: Associate Professor Abbas Mohajerani. Image Credit: RMIT University
Australian waste-to-resource company Repurpose It have opted for Volvo Construction Equipment’s excavators and loaders for their Victorian plant.
The five new machines will assist the company’s loading and handling duties to assist in their recycling operation that sees large quantities of waste material re-used in the construction industry.
One Volvo EC250DL and two EC220DL units were chosen for excavation duties on the site, Repurpose It aims to input the tools on general earthmoving, screen feeding, sorting and stockpiling projects.
The company chose the L110F and L220H two-wheeled loaders for their loading work which will see hopper fed into their new recycling plant.
Repurpose It CEO George Hatzimanolis said that the company was happy to choose Volvo as the manufacturer alings with their energy efficiency commitments and engineering values.
“Our business is focused on reducing our carbon footprint and working towards a more sustainable future, as is Volvo,” Mr Hatzimanolis said.
“We were also attracted to the quality that comes with Volvo machines.”
The two EC220DL excavation units chosen for the site uses Volvo’s modern D6 diesel engine reporting 10% extra fuel efficiency over its competitors.
The Volvo machines were purchased from Dandenong’s CJD Equipment, Volvo’s exclusive Australian distribution partner.
Victoria’s reliance on extractive resources is increasingly becoming an unviable prospect, but a new solution will soon see more construction and demolition materials recovered in the state.
The NSW EPA has partnered with police, the ACT Government and local councils to target rogue operators supplying waste soil from construction sites advertised as clean fill to property owners.
Compliance and road side checks were part of the crackdown to ensure fill going to a site had the appropriate council approval to accept it.
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By targeting rogue operators during transport, the NSW EPA aims to stop contaminated and non-compliant materials being illegally dumped or passed off as clean fill to innocent land owners.
Accepting large amounts of fill can create potential dust issues and pollute waterways.
NSW EPA Senior Officer Janine Goodwin said in some of the worst cases, operators are providing unsuspecting residents with soil cheaply or for free that is contaminated with construction and demolition waste, heavy metals or even asbestos.
“Councils require landholders to apply for development approval to bring larger volumes of fill onto private property. If a property is used to accept this material without proper council approval, both the landholder, the owner of the waste and the transport contractor may be fined and the landholder may discover they have to pay to have the material removed,” Ms Goodwin said.
“We have been checking things like documentation to make sure the waste is correctly classified and going to a site that has consent to accept it.”
ACT EPA’s Narelle Sargent said waste being transported between the ACT and NSW needs approval.
“Transporters and builders are on notice that the illegal transport and disposal of waste will not be tolerated in the ACT region, and large penalties apply,” Ms Sargent said.
Recycled construction and demolition (C&D) waste will be trialled as road base for use on the Kwinana Freeway widening project, WA.
The project is the first major road in WA that will use recycled materials as road base to boost the state’s recycling performance.
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The trial will take place between Russell Road and Roe Highway and will use about 25,000 tonnes of recycled C&D product.
Main Roads WA will work with the Waste Authority and the Department of Water and Environment Regulation (DWER) for the trial.
A new product testing scheme will aim to help C&D recyclers with the costs associated with meeting the appropriate specifications are free of contaminants and asbestos. An independent audit testing scheme aims to provide additional support.
The pilot aims to improve confidence in using recycled C&D products and supporting the state’s waste diversion target. Its findings will be used to establish the WA Government’s Road to Reuse program.
WA Environment Minister Stephen Dawson said the demonstration project is the beginning of a new practice for the government.
“It will demonstrate to local governments and industry that recycled content is usable and value for money, redressing the concerns from many years ago that effectively stopped any reuse of valuable construction and demolition materials,” Mr Dawson says.
“This partnership between DWER, the Waste Authority and Main Roads is a huge step forward for the reduction of construction and demolition waste in Western Australia.
“By using recycled construction and demolition products in projects across the state, we can help meet our landfill diversion targets and focus on recycling materials.”
WA Transport Minister Rita Saffioti said the interagency partnership is key to ensuring the ongoing use of recycled material in WA.
“Roads to Reuse establishes a strict testing regime to reduce the risk of contaminants to below allowable limits – protecting people and the environment,” she said.
A new sustainability strategy for Canberra has been released that set targets for waste reduction, increased recycling and reductions in greenhouse gas emissions.
It is part of Canberra’s City Renewal Authority’s goal to become a world class sustainable capital city as part of its built environment and design.
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Targets identified in the strategy for 2025 include waste and recycling management plans aim to target 95 per cent of construction resource recovery and increasing the onsite capture and reuse of organics, recyclables and bulky waste by 20 per cent over the 2015 level.
To hit these targets, the strategy plans to deliver exemplars of waste resource recovery in construction and operation phases of Canberran projects.
The City Renewal Authority’s sustainability program uses sustainability policies from across the ACT Government to form the strategy for the City Renewal Precinct.
City Renewal Authority CEO Malcolm Snow said Canberrans have a high expectation that their city be environmentally, socially and economically sustainable.
“We want a city that will still support future generations, so we need to create a city now where sustainable living is a part of everyday life. This responds to the community’s expectation for government leadership on sustainable development and access to green space,” Mr Snow said.
“Social and environmental sustainability are vital elements of our program as we implement the design-led and people-focused renewal of our city precinct.
“We will make Canberra an even more liveable city by reducing its environmental footprint and setting a high standard of social sustainability,” he said.
Mr Snow said the Authority has set these targets to influence outcomes across the precinct as new development proposals are submitted.
“Achieving these outcomes will require collective urban leadership from government, the community and the private sector. It is in all our interests that the city grows in a way that improves the lives of current and future generations,” he said.
“We can’t do this alone and we look forward to working with all stakeholders to help make the City Renewal Precinct an even better place for people to work, live and visit.”
The NSW Government has initiated a crackdown on asbestos waste, introducing stronger measures to protect the community and environment from rogue construction and demolition waste operators.
A reform package has been announced and will increase on the spot fines for illegally transporting or disposing of asbestos waste by tenfold.
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Construction and demolition waste facilities will also face tougher inspections and handling rules, along with new fines for illegally digging up landfills.
Under the changes, construction and demolition waste facilities will have tighter inspection controls and constant video monitoring. Facilities must also comply with stringent waste storage rules and provide evidence that staff are properly trained.
Incentives are also available for those doing the right thing, with a 75 per cent levy discount for some types of construction and demolition waste that meets specification to be applied as cover material.
The changes were introduced in the Protection of the Environment Operations Legislation Amendment (Waste) Regulation 2018, which will come into effect in May 2019 to allow the industry time to adjust.
NSW Environment Minister Gabrielle Upton said it is a top priority that stronger penalties act as a deterrent and that waste facility operators improve the way they manage construction and demolition waste.
“By giving the NSW Environment Protection Authority (EPA) stronger penalties, it can more effectively hold the waste industry to account as well as encouraging good behaviour.
“On the spot fines for illegal asbestos transport and disposal have increased from $750 for an individual and $1,500 for a corporation to $7,500 and $15,000.
Ms Upton said the reforms follow comprehensive consultation with local councils, waste facility operators, industry bodies and the community.
“Poor practices were identified particularly at a number of facilities handling construction waste. That is why there are now tougher standards and procedures to safeguard the environment and community.”
“There is also a new, $15,000 on-the-spot fine and penalties of up to $44,000 for illegally digging up old landfills. From now on, landfills can only be dug up in cases of emergency or with specific permission of the EPA,” she said.