Concrete is the world’s second most-consumed substance after water, but it’s also among the most damaging to the planet. As India pushes for a greener built environment, new materials and methods are emerging to cut the sector’s carbon load.
Across the industry, sustainability is no longer a footnote. Lean construction, modular building, prefabrication and smarter demolition practices are becoming mainstream. Every stage of the building lifecycle is now under scrutiny, from design to development to end-of-life, because the climate clock is ticking.
And at the heart of the debate sits concrete, the old workhorse that has turned into one of construction’s biggest climate challenges.
Why concrete is a problem
Cement and concrete together emit more carbon than the entire aviation sector. They account for nearly 8 percent of global CO2 emissions. Concrete consumption has exploded, doubling its emissions in the last two decades. Today we use around 30 billion tonnes of it every year, making it the second most consumed substance on Earth.
For a sector serious about reaching net-zero targets and aligning with global sustainability goals, finding alternatives is no longer optional.
Below are 12 promising replacements and supplements that can cut emissions and reshape construction’s material future.
- Green concrete
Green concrete keeps the familiar format but swaps out cement for waste materials from power plants, mines and incinerators. It needs less energy to produce, emits less carbon, and is more durable. It also reduces water permeability and cracking while lowering costs by cutting dependence on new raw materials.
- Aggregate replacement (like papercrete)
Instead of sand and gravel, this mix uses materials such as glass, plastic, rubber, paper and clay. These substitutes can reduce energy use and costs. The trade-off is that the material’s strength or corrosion resistance may change, depending on the chosen aggregate.
- Ashcrete
Made with fly ash from coal combustion, ashcrete is about 93 percent recycled. It improves strength and durability and lowers project costs. The drawback is slower setting time, which can delay construction schedules.
- Micro silica (silica fume)
A byproduct of silicon metal production, micro silica boosts strength and corrosion resistance by reducing permeability. It can replace up to 12 percent of cement. However, it leads to a denser, less workable mix, making construction trickier.
- Blast furnace slag (GGBFS)
Sourced from steel manufacturing, this refined material enhances workability and reduces permeability. Its limitation is low early strength and longer setting time, which makes it unsuitable for projects needing a quick turnaround.
- Recycled concrete debris
Concrete makes up nearly 85 percent of construction waste. Instead of leaving it as rubble, it can be crushed and reused. This reduces emissions instantly, improves stability and speeds up production.
- Grasscrete
Used mainly for pavements, grasscrete leaves patterned gaps for grass and soil. It improves drainage, cuts heat absorption, and reduces the total concrete required. It’s often paired with other sustainable mixes.
- Recycled plastic waste
Plastic waste can be used as a partial aggregate, helping cut CO₂ emissions and transport costs. While sustainable, the mix can lose strength because plastic doesn’t bind as well as sand.
- Mycelium
Made from the root-like fibres of mushrooms mixed with organic matter, mycelium forms a lightweight, fire-resistant, biodegradable building block. It can be moulded into almost any shape. Its limitation is low strength compared to concrete, but it’s gaining traction for non-load-bearing uses.
- Hempcrete
Hemp fibres make this material light, breathable and thermally efficient. Hemp grows quickly, making it a strong sustainability contender. Hempcrete is already being used for insulation and walls but is not as strong as concrete for major structural components.
- Self-healing concrete
This “smart” material uses bacteria to fill cracks when they appear, extending the life of structures. It reduces repair costs and improves safety, especially in aging buildings.
- Bamboo
Strong, flexible and fast-growing, bamboo has been a construction staple for centuries. Today it is being re-evaluated as a sustainable replacement for steel or concrete in flooring, scaffolding and even roofing. It offers high tensile strength and excellent corrosion resistance.
Sustainable materials aren’t just experimental anymore—they’re becoming essential tools for an industry racing to cut emissions. As concrete alternatives grow stronger, cheaper and more accessible, they’re set to play a central role in the next chapter of India’s green building movement. This shift marks not just an environmental need but a complete rethink of how we shape the spaces we live in.
