Category: Construction industry

3D-printed concrete to help build $147B UK high-speed rail system

Read the full story at Smart Cities Dive.

Skanska is planning to use 3D-printed concrete in its work on HS2, a high-speed rail system reported to cost as much as $147 billion, under construction in the U.K. 

The joint venture between Skanska, U.K. civil contractor Costain and Austrian contractor Strabag will employ a technology called “Printfrastructure” that will print concrete structures on site instead of shipping them in prefabricated slabs or mixing and pouring it at the location. 

The machine is also capable of going into physically restricting spaces, removing the costs of sending people in to do the same job. Proof-of-concept trials are due to begin next spring, according to an HS2 press release.

Construction industry considers its role in avoiding PFAS

Read the full story at Engineering News-Record.

While awareness and regulation of per- and polyfluoroalkyl substances (PFAS) has been on the rise, the focus has often been on their presence in firefighting foams and water-, grease- and stain-resistant products like Teflon. But the chemicals also are found in a wide variety of building materials, and the construction industry could have a significant role in limiting their use.

Can concrete, a major CO2 emitter, be made greener?

Read the full story at PBS NewsHour.

After water, concrete is the most consumed substance on the planet and its production is expected to grow from 4.4 billion tons to 5.5 billion tons by 2050. But its production, which involves cement, comes at a huge environmental cost — accounting for almost eight percent of carbon emissions globally. Mori Rothman reports on the industry’s attempt to reduce concrete’s carbon footprint with cleaner cement.

Scientists recycle demolition waste into eco-friendly 3D printable concrete

Read the full story at 3D Printing Industry.

Scientists based at the Swinburne University of Technology and Hebei University of Technology have managed to turn construction waste into a sustainable new 3D printing material. 

Using recycled concrete aggregate, ceramsite particles and desert sand, the team have been able to formulate a low-cost extrudable building material, in three different particle gradings. During initial testing, the novel concrete substitute demonstrated a self-supporting ‘skeletal’ effect, potentially lending it the strength and durability needed for deployment within heavy-duty construction applications.

Pittsburgh pursues sustainable deconstruction policy to salvage building materials

Read the full story at Waste Dive.

The City of Pittsburgh is pursuing a building deconstruction policy meant to spur the potential recovery, recycling and reuse of materials from certain city-owned condemned structures. Leaders say potential benefits of such a policy include removing blight from neighborhoods while decreasing waste sent to landfills, advancing climate action goals, and opening opportunities for job training.

Mayor Bill Peduto signed an executive order last week tasking the city with creating a process for identifying and assessing structures potentially eligible for sustainable deconstruction, with particular focus on historically Black business districts and low-income communities.

There are currently more than 1,700 condemned structures in Pittsburgh, said Sarah Kinter, the city’s director of the Department of Permits, Licenses and Inspections. Pittsburgh will move forward with a pilot this year on deconstruction of city-owned properties, but also plans to create material recovery standards for city-funded demolitions. The city hopes to begin deconstruction projects this fall, Kinter said.

Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

Vitale F, Nicolella M. “Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review.” Sustainability 13(5), 2756.

Abstract: Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

Concrete from Halifax startup used in new Amazon HQ cuts emissions, attracts high-profile financing

Read the full story in the Globe & Mail.

As Inc. builds its massive second headquarters in Virginia, the company is using concrete strengthened by one of the most quietly successful startups from Canada’s East Coast.

CarbonCure Technologies Inc. has honed its techniques for injecting carbon dioxide into concrete for more than a dozen years. The process adds enough strength to the building material to cut the amount needed for a project by about 5 per cent. Doing so also significantly reduces the environmental impact of using concrete: For every tonne of carbon dioxide injected, the Halifax company says it can save about 40 tonnes of emissions.

Proposed model shows potential for circular practices in construction steel

Read the full story in GreenBiz.

Contrary to popular belief, a profitable business model for reused construction steel is not nearly as impossible as one may believe.

Steelmakers have almost perfected the “recycle” element of the four hierarchical elements of the circular economy — reduce, reuse, remanufacture and recycle — with steel recycling rates of almost 90 percent.

Despite the recycling success, however, the steel industry is increasingly facing pressure to decarbonize. Recycling steel is still both energy- and cost-intensive, and both steelmakers and their customers must go further to reduce environmental impacts. One way to do this is to shift to a reuse model.

Enablers and Barriers for Creating a Marketplace for Construction and Demolition Waste: A Systematic Literature Review

Caldera S, Ryley T, Zatyko N. (2020).. “Enablers and Barriers for Creating a Marketplace for Construction and Demolition Waste: A Systematic Literature Review.” Sustainability. 12(23), 9931.

Abstract: Rapid population growth and urbanization have led to an increase in Construction and Demolition (C&D) waste, prompting government and industry bodies to develop better waste management practices. Waste trading has emerged as a targeted intervention to divert waste from landfill sites and create a second life for waste material. This paper examines key barriers and enablers influencing the creation of a marketplace for waste trading. A systematic literature review was undertaken to examine global efforts in creating a marketplace for C&D waste. A framework on enablers and barriers for developing a marketplace for C&D waste emerged from the review, based on market-based, operational, and governance factors. References demonstrated that markets for materials such as glass and metals have already been established, but there are increasing marketplace opportunities for other recycled materials. Technology-based market applications are emerging as targeted interventions to facilitate online trading, which will provide a more accessible and user-friendly marketplace for sellers and buyers. Further research should test the complex interactions between people and technology associated with online waste trading platforms, as well as help develop the business case for a C&D waste marketplace.

3 ways contractors are using technology to reduce waste — and increase margins

Read the full story at Construction Dive.

Contractors often focus on increasing margins and a number of technology solutions to enhance productivity and efficiency. But a more pragmatic strategy commonly gets ignored — reducing waste.

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