The construction industry continues to trend toward sustainable construction practices to reduce carbon emissions and environmental impact.
According to Buildpass, sustainable construction has seven principles: sustainable design, durability, energy efficiency, waste reduction, indoor air quality, water conservation, and sustainable building materials.
The construction industry is taking significant strides in its race to become sustainable. Increasing the active use of recycled aggregate materials reduces its environmental impact and carbon footprint, demonstrating its commitment to a more sustainable future.
Virgin aggregates, such as naturally occurring sand, rock, and gravel, are finite resources and could be depleted soon. A study that analyses the environmental impacts of virgin aggregates reveals that mining and extracting them from the earth can cause serious ecological consequences. It notes that near-site qualitative impacts include landscape deterioration, noise, dust, potential sedimentation, and pollution of water bodies. Additionally, land use and land use change could result in habitat loss, ecosystem erosion, greenhouse gas releases, and air quality deterioration.
The use and operation, including the energy required to operate these heavy equipment, trucks, and machinery to harvest, process, and transport these aggregates, also adversely impact the environment.
Recycled aggregate is a sustainable construction material sourced from demolished buildings, roads, bridges, and other structures. Hundreds of thousands of tons of this debris are generated every year.
Aggregates play a crucial role in the concrete mix. They increase their volume while ensuring minimal air is trapped within the structures. Aggregates come in various sizes. The larger and coarser ones act as the skeletal structure for the mixture. Smaller particles fill the spaces between these larger particles, and cement particles fill the tiniest gaps, which bind the structure together.
Use of virgin vs. recycled aggregates
When it comes to the use of virgin aggregates vs recycled aggregates in construction, a study by de Bortoli shows that virgin gravel and sand are the most extracted non-mineral resources in the world, respectively, representing 41 and 31% of the global production.
Recycled aggregates only represented an estimated 9% of the aggregate market 2022. The limited usage of recycled aggregates is partly due to the reduced quality of the material compared with virgin aggregates.
Benefits of using recycled aggregates
Some governments offer tax rebates to incentivize companies to invest in fuel-efficient technologies. Construction industries looking for sustainable solutions can incorporate recycling debris, which provides savings because it can lower cement content and reduce their environmental impacts due to the reduced need for natural aggregates and overall carbon emissions linked with concrete production.
Additionally, recycling aggregates from construction and demolition helps support a circular economy by diverting waste from landfills and reusing it for construction, giving it new life that will otherwise be treated as waste.
Applications of recycled aggregates
Some civil infrastructure projects prefer virgin aggregates due to strict standards and where precise specifications are critical, like load-bearing applications.
Recycling aggregates are sometimes structurally equivalent to virgin aggregates when used as road bases or subbases.
Other applications of recycled aggregates include:
- Bases for foundations and roadways
- Drainage and septic systems,
- Landscaping,
- Backfill for retaining walls,
- Pipe bedding
- Utility trenches backfill for pipework
- Interlocking blocks
- The base for walkways, patios, and pavers,
- Animal footing
- Non-load bearing and some load-bearing ready-mix concrete
- Masonry sand,
- Asphalt/bituminous concrete
Using recycled aggregates for the above applications promotes sustainability and offers many benefits to the environment, climate, and businesses, such as lowering costs.
It also reduces the need for mining virgin aggregates with limited resources and reduces the adverse effects on the environment and carbon emissions linked to mining and processing them.
The construction sector significantly contributes to greenhouse gas emissions and waste, from the production of building materials to the construction and operation of buildings and infrastructure.
Some studies suggest that construction contributes up to 50% of climate change. The good news is that there is a growing trend in the industry to make positive changes in its practices to reduce its adverse effects on the environment and the climate.
Sources:
Sadler, A. (2021, May 21). The 7 Principles of Sustainable Construction. Retrieved from https://buildpass.co.uk/blog/the-7-principles-of-sustainable-construction/
Comparing Recycled Aggregate and Virgin Aggregate for New Construction Projects. (2024, January 17). McLanahan. Retrieved from https://www.mclanahan.com/blog/comparing-recycled-aggregate-and-virgin-aggregate-for-new-construction-projects
Singh, A., Miao, X., Zhou, X., Deng, Q., Li, J., Zou, S., & Duan, Z. (2023, October 2023). Use of recycled fine aggregates and recycled powders in sustainable recycled concrete. Journal of Building. Retrieved from https://doi.org/10.1016/j.jobe.2023.107370.
Using Recycled Concrete Aggregate. (2019, February 28). Specify Concrete. Retrieved from https://www.specifyconcrete.org/blog/using-recycled-concrete-aggregate
Bortoli, A. (2023, August 20). Understanding the environmental impacts of virgin aggregates: Critical literature review and primary comprehensive life cycle assessments. Journal of Cleaner Production. Retrieved from https://doi.org/10.1016/j.jclepro.2023.137629
Leave a Reply