+
Groundbreaking: Recipe for zero-carbon cement discovered
Concrete

Groundbreaking: Recipe for zero-carbon cement discovered

A breakthrough from Cambridge aimed at tackling CO2 emissions from concrete and steel production simultaneously. It suggests that throwing old concrete into steel-processing furnaces could yield both purified iron and "reactivated cement" as a byproduct, potentially leading to carbon-zero cement production if renewable energy is used.

Concrete production is a significant contributor to global CO2 emissions, accounting for approximately 8% of the total. However, recycling concrete into a usable form for new structures has been challenging.

Efforts to make concrete more environmentally friendly have included altering its composition to reduce pollution, such as substituting less harmful ingredients like limestone, or designing concrete to absorb more CO2 from the atmosphere over time. In this study, researchers from Cambridge explored the conversion of waste concrete back into clinker, the dry component of cement, for reuse.

Dr Cyrille Dunant, the lead author of the study, mentioned having a notion from previous research that crushing old concrete, removing sand and stones, heating the cement to eliminate water, and then forming clinker might be feasible. They experimented with using an electric arc furnace, commonly employed for recycling steel, to aid this process.

In traditional steel recycling using an electric arc furnace, a flux material, typically lime, is utilised to purify the steel. This substance captures impurities, rises to the surface, and forms a protective layer to prevent exposure to air. Afterward, the used flux is discarded as waste.

In the Cambridge method, the lime flux was replaced with recycled cement paste. Remarkably, not only was the steel successfully purified, but the leftover slag could be rapidly cooled to produce new Portland cement. The resulting concrete exhibited similar performance to conventional concrete.

A breakthrough from Cambridge aimed at tackling CO2 emissions from concrete and steel production simultaneously. It suggests that throwing old concrete into steel-processing furnaces could yield both purified iron and reactivated cement as a byproduct, potentially leading to carbon-zero cement production if renewable energy is used. Concrete production is a significant contributor to global CO2 emissions, accounting for approximately 8% of the total. However, recycling concrete into a usable form for new structures has been challenging. Efforts to make concrete more environmentally friendly have included altering its composition to reduce pollution, such as substituting less harmful ingredients like limestone, or designing concrete to absorb more CO2 from the atmosphere over time. In this study, researchers from Cambridge explored the conversion of waste concrete back into clinker, the dry component of cement, for reuse. Dr Cyrille Dunant, the lead author of the study, mentioned having a notion from previous research that crushing old concrete, removing sand and stones, heating the cement to eliminate water, and then forming clinker might be feasible. They experimented with using an electric arc furnace, commonly employed for recycling steel, to aid this process. In traditional steel recycling using an electric arc furnace, a flux material, typically lime, is utilised to purify the steel. This substance captures impurities, rises to the surface, and forms a protective layer to prevent exposure to air. Afterward, the used flux is discarded as waste. In the Cambridge method, the lime flux was replaced with recycled cement paste. Remarkably, not only was the steel successfully purified, but the leftover slag could be rapidly cooled to produce new Portland cement. The resulting concrete exhibited similar performance to conventional concrete.

Related Stories

Gold Stories

Next Story
Infrastructure Urban

KONE Opens India's First Digital Experience Centre in Pune

KONE, a global elevator and escalator manufacturer, has inaugurated its first Digital Experience Centre (DEC) in India, located in Pune. The facility aims to showcase how artificial intelligence (AI), connectivity and data-driven technologies can enhance customer experiences and improve building operations.The centre was inaugurated by Jussi Herlin, Executive Vice Chair, KONE Corporation; Philippe Delorme, President and CEO, KONE; and Nandan Nilekani, Co-founder and Chairman of the Board, Infosys.Designed as an interactive customer environment, the facility demonstrates digital solutions cover..

Next Story
Infrastructure Urban

CII GreenCo Launches Circularity Guidelines for Indian Industry

The Confederation of Indian Industry (CII) GreenCo Council has launched the CII GreenCo Circularity Guidelines – Pilot Version at the 17th CII GreenCo Waste & Resource Management Summit 2026 in Chennai. The initiative aims to strengthen resource efficiency, waste reduction and circular economy practices across Indian manufacturing and process industries.The guidelines introduce a structured framework with circularity indices covering raw materials, consumables, packaging and other resource inputs. These indicators will help industries assess existing practices, identify opportunities to ..

Next Story
Infrastructure Energy

Global Electronics Association Launches IPC-1783-CO2E Standard

The Global Electronics Association has introduced IPC-1783-CO2E, a new international standard aimed at improving consistency, transparency and comparability in product carbon footprint reporting across the electronics manufacturing industry.The standard, titled International Standard for Data Collection and Reporting of CO2 Equivalent (CO2e) Emissions for the Electronics Manufacturing Supply Chain, provides industry-specific guidance for collecting, estimating and reporting carbon emissions data.With increasing regulatory requirements and customer expectations, electronics manufacturers face c..

Advertisement

Subscribe to Our Newsletter

Get daily newsletters around different themes from Construction world.

STAY CONNECTED

Advertisement

SPECIAL OFFER
QR Code