Sustainable Building Materials: Engineering A Greener Future

How innovative building materials are shaping the future of eco-friendly architecture

Built with 1.5 recycled plastic bottles, The EcoArk Pavillon in Taipei, Taiwan is a feat of sustainable architecture. Image provided by TOPIA

The construction industry is one of the leading causes of greenhouse emissions, responsible for a staggering 37% of global emissions. Traditional materials like concrete and steel require large amounts of energy to produce, worsening the crisis. To address this issue, engineers and architects are turning towards more eco-friendly building materials that don’t sacrifice strength and efficiency of buildings.

Self-Healing Concrete

Concrete is one of the most widely used construction materials, but it cracks over time, leading to costly repairs and replacements. An alternative to this is by implementing self-healing concrete which uses bacteria or polymer agents that automatically repair cracks, reducing material waste and improving durability over time. In bacteria based concrete, as cracks appear in the concrete, the bacteria becomes exposed to oxygen and water. This causes a reaction in which the bacteria begin to produce calcium carbonate, also known as limestone, effectively sealing off the opening in the concrete, ensuring longevity. Polymer infused concrete, another material used by engineers, works by adding a polymer agent to regular concrete mix, which chemically reacts to the concrete, sand, and water in the mixture. The mixture aggregates, creating a stronger and durable composite material with improved resistance to water, chemicals, and further degradation.

Stronger, Greener Wood

Modern advancements in engineered wood offer renewable and carbon-negative alternatives to concrete and steel in construction. Cross laminated timber (CLT) and glue laminated timber (glulam) are popular options that offer architects sustainability without sacrificing strength and flexibility. CLT is made of layers of timber stacked on each other crosswise and glued together to form large panels. Glulam, another useful material, is made by bonding layers of timber with high-strength adhesives. Both these products are extremely versatile in construction, offering strength and stability in buildings; Additionally, a natural source of building material, bamboo, has also proven to be an efficient material in reducing carbon footprint. Since bamboo has a high strength to weight ratio, it makes it very useful for structural building, while also being fire and weather resistant. These materials, both timber and bamboo, are sustainable because they absorb carbon dioxide during their growth, reducing carbon footprint.

Recycled and Upcycled Waste

The construction industry generates millions of tons of waste annually, in which most ends up in the landfill, thrown away without thought to future use. These include materials from destroyed or wrecked houses and buildings. Sustainable architecture incorporates these materials such as recycled concrete, plastics and glass into new projects to reduce environmental impact. Recycled concrete aggregates (RCA), is concrete from old projects that becomes repurposed for roads and new buildings. RCA is made by crushing, screening, and washing concrete from construction waste. Then, it gets combined with aggregate (grains or fragments of rock), to create concrete. Additionally, engineers will take plastic waste, and instead of going to the landfill, will actually use it. Plastic waste becomes compressed to form durable, lightweight bricks and panels, which as aggregate, insulation, roofing, and many other purposes. Finally, recycled glass can be integrated into concrete and asphalt in a crushed up form, or repurposed to make new glass tiles.

Carbon Absorbing Cement

Traditional cement making processes release 8% of global carbon emissions, and instead of being detrimental to the environment, an alternative would be producing carbon-absorbing cement that reverses the impact, transforming buildings into carbon sinks by trapping carbon dioxide instead of emitting it. For example, CarbonCure technology is where people inject captured carbon into cement, mineralizing and staying trapped forever in the buildings. However, this still doesn’t fix the problem of releasing emissions during production. To solve this,  Companies in Japan jointly designed CO2-SUICOM, which is a type of concrete that actively absorbs carbon dioxide while it hardens, making it a "carbon-negative" concrete with net-zero or even negative CO2 emissions compared to traditional concrete production.

Sustainable building materials like self-healing concrete, CLT, recycled materials, and carbon-absorbing cement are reshaping architecture and civil engineering, reducing environmental impact, and improving the durability and endurance of buildings. As these materials become more widespread and used more, they will play a crucial role in creating eco-friendly cities, proving that sustainability and innovation can coexist in modern construction.