We need alternatives to cement:
As demonstrated in the Chatham House report, while cement (an essential element for concrete manufacturing) is extremely detrimental to the greenhouse effect and climate crisis –representing about 8% of global CO2 emissions–, its global production is nevertheless expected to increase over the next 30 years.
Creative alternatives to concrete – Sidmouth Solarpunk
There are alternatives:
Seen as one of the great promises for the future of construction, carbon concrete mixes strength, lightness and flexibility. In addition, at a time marked by a serious environmental crisis that puts the construction methods of the industry in check, carbon concrete emerges as an alternative that approaches the guidelines of sustainability.
Alternatives to reinforced concrete – Vision Group for Sidmouth
And there are more:
CarbonCure, for example, seeks to reduce carbon dioxide emissions in a very different way. The Canadian startup has developed a process called CO2 Mineralization, which consists of injecting carbon dioxide into the concrete mix and making it react with calcium ions in the cement to form a nano-sized mineral, Calcium Carbonate, which is embedded in concrete, making it more resistant...
Solidia Tech has been experimenting with a new cement recipe that replaces limestone with the mineral wollastonite, which does not emit carbon dioxide, as it does not require heating. In addition, it traps carbon dioxide from the air during the curing process, creating a product with negative emissions. As this article shows, Solidia’s cement concrete blocks capture about 240 kg of carbon dioxide for every 1,000 kg of cement used in the mix. This is in addition to lower amount of emissions produced during concrete manufacturing.
BioMason is a North Carolina startup with a distinct approach, producing concrete without Portland cement or carbon dioxide emissions. Instead of Portland cement, biocement is used to join sand and gravel. By incorporating recycled aggregates with live bacilli microbes, it triggers the combination of carbon and calcium to create limestone crystals, without the need for heating. While traditional concrete can take up to 28 days, Biomason biocement® reaches its final resistance in less than 72 hours of growth. The final material consists of approximately 85% granite from recycled sources and 15% biologically cultivated limestone.
Engineers from Lancaster University in the UK have worked in collaboration with Cellucomp Ltd UK to study the effects of adding “nanoplatelets” extracted from plant root fibers to improve the performance of concrete mixes. Research has shown that composite plant concretes, made from vegetables such as beets or carrots, have a structurally and environmentally superior performance over all commercially available concrete additives such as graphene and carbon nanotubes at a much lower cost.
Cement Can Be A (More) Sustainable Material | ArchDaily
Finally, from Lancaster University and Cellucomp – a video from some time back, showing that we really can be using these approaches:
