Exploring Eco-Friendly Concrete Options for Sustainable Construction
Construction contributes to significant pollution and resource depletion, so it’s important for builders and contractors to explore eco-friendly materials. These alternatives to traditional concrete offer durability and strength without a large environmental impact.
Sustainable concrete uses recycled materials and production processes that minimize waste, CO2 emissions, and resource consumption. Here are a few ways this can be achieved:
Recycled Concrete
Construction projects frequently involve demolition work that can leave contractors with a lot of old concrete. Instead of dumping this material into landfills where it can take up valuable space and hinder construction traffic, these materials can be recycled. Concrete recycling involves crushing the concrete and reusing it as aggregate in new concrete construction.
The process reduces the amount of landfill waste, helps conserve natural resources used in creating new concrete, and eliminates transportation costs. It also allows for a higher quality of concrete than is possible using only natural aggregates. This page provides valuable information on the environmental and economic benefits of concrete recycling.
Crushed concrete can be used in construction as an alternative to traditional gravel or sand and is a great choice for backfill, sub-base, or fill material. However, this type of concrete has a lower level of workability than new production concrete, so it may not be the right choice for all applications. It’s also not ideal for foundations, sidewalks or other visible elements in projects where aesthetics are a priority.
Fly Ash Concrete
A byproduct of coal combustion in power plants, fly ash is used to partially replace cement in concrete construction. This re-use of industry waste helps to reduce energy consumption and carbon emissions during concrete production, as well as curb global warming.
Fly ash improves concrete workability, pumpability, cohesiveness, finish, and durability. It also decreases permeability, increases sulfate resistance, reduces corrosion of reinforcing steel, and lowers the heat of hydration required for early strength development.
Since the particles in fly ash are spherical and have a similar size range as portland cement, it’s possible to decrease water content for concrete mixes while still achieving a desired mix design. However, the quality of fly ash can vary, and low-calcium class F fly ashes may need to be screened using a dry process or wet process based on froth flotation to ensure the highest level of contaminant removal. This ensures that the final product meets proper concrete specification requirements.
Ground Granulated Blast Furnace Slag Concrete
Ground granulated blast furnace slag (GGBFS) is an eco-friendly concrete material that recycles an industrial byproduct. It uses less water and energy during production than traditional concrete mixes, resulting in fewer greenhouse gas and carbon dioxide emissions.
In addition, GGBFS reduces the heat of hydration in concrete, making it more energy efficient. Additionally, it helps concrete withstand harsh climate conditions such as freeze-thaw cycles and saltwater exposure. It can also be used as an effective insulator for roads and pavement base courses over frost susceptible soils.
Researchers found that using GGBS can decrease the amount of contractions during hardening, improving flexural strength in concrete. This is because GGBS has an asperity lower than sand and a grinding fineness that diminishes hardening contractions. It can also improve tensile strength in bending. Lastly, it can significantly increase the compressive strength of concrete.
Energy-Efficient Concrete
Energy-efficient concrete utilizes recycled materials and industrial byproducts that require less cement to produce. This variant of concrete can reduce CO2 emissions from production and offer sustainability benefits throughout the construction process. By using a water-reducing admixture, these alternative concrete solutions can also contribute to onsite water conservation.
Sustainable concrete options are environmentally friendly and can be sourced locally, reducing transportation-related carbon footprints. They are long-lasting and durable, which eliminates the need for regular maintenance, resulting in further savings on energy costs.
Concrete’s thermal mass properties also help to protect buildings from outdoor temperature swings, resulting in reduced energy consumption. This translates into substantial savings on utility bills for building occupants.