CIMA Bukit Ketri plant has trees planted in the surroundings as part of its decarbonisation effort.

Use of cement with lower carbon footprint needs scaling up

By: Yip Wai Fong

The urgency in Malaysia's construction industry to curb CO2 emissions, driven by climate change and increased ESG awareness, has led to rising interest in low-CO2 cement products. Traditional cement, specifically Portland cement, is one of the highest CO2 emitters. 

Cement is a major binding ingredient in ready-mix concrete, which comprises about 60% of a building’s construction materials. A study by the Construction Industry Development Board (CIBD) found that cement and ready-mix concrete, along with bricks, steel and metal, and steel reinforcement combined are responsible for 92% of the 76 million tonne CO2 equivalent (tCO2eq) emitted by the industry between 2017 and 2019. 

“The current production of cement is not green. Worldwide, it is directly responsible for up to 8% of global CO2 emissions,” said Malaysia Green Building Council (malaysiaGBC) president Serina Hijjas, citing the International Energy Agency. “If the cement industry were a country, it would be the world’s third highest emitter of greenhouse gas after the USA and China.” 

Serina also acknowledges that the use of lower CO2 cement mixes is gaining traction. 

“As a result of increased awareness and efforts to mitigate global climate change, the use of lower-CO2 cement mixes is becoming increasingly popular and in demand to feed the construction industry that is tracking their ESG targets. Depending on the type of use, lower-carbon cement can include fly ash or other binding agents to replace the amount of cement in the concrete mix, this incrementally reduces the material’s embodied carbon without compromising the strength and other properties of the mix,” she explained. 

Cement Industry of Malaysia Bhd (CIMA) strategy and transformation head Hannah Lyana Lee Abdullah also said demands for such cement products are steadily increasing, driven by awareness of sustainability issues. 

According to the CIMA website, construction works that have utilised its green-certified (by Singapore Environment Council or SIRIM) cement products include the Second Penang Bridge, Permata Sapura Tower, Klang Valley Mass Rapid Transit and Solaris Parq. 

“While reliance on Portland cement persists, many stakeholders are starting to recognise the long-term environmental and economic advantages of adopting more sustainable alternatives,” Hannah said, adding that CIMA products integrate pulverised fly ash or ground granulated blast-furnace slag (GGBS) to lower the clinker ratios, minimise landfill waste and CO2 emissions. 

Benefits

Fly ash supplier Acegreencemt group chief executive officer Arian Haddadian said products that incorporate fly ash as supplementary cementitious material enhance the cement-mix performance and are priced lower. 

“Fly ash is waste produced by the coal power plant and it is not just any waste, it improves the quality of buildings (that use it). Fly ash’s advantage for me is, it doesn't need a lot of treatment after being produced,” he explained, adding that Acegreencemt supplies up to two million tonnes of fly ash and 1.5 million tonnes of GGBS, another type of supplementary cementitious material from recycled waste. 

“I’m not saying it is 100%, but in most cases, the products that incorporate fly ash or GGBS are more affordable (than those which don’t) and the quality is no question,” he said. 

Acegreencemt is also in collaboration with CIBD’s subsidiary Construction Research Institute of Malaysia (CREAM) to conduct tests on fly ash with the view to increasing its adoption. 

“We are sponsoring studies with CREAM to test fly ash in different grades of concrete in different forms, fresh or hardened, to check its properties and effect on a building’s lifespan under local context,” he shared.

More adoption

To widen adoption, systemic changes are needed including to correct the perception of higher cost and lower performance, said Hannah. 

“The cost is sometimes higher due to the stringent handling of waste materials and additional processes, such as alternative raw materials or advanced technologies for reducing carbon footprints, which are typically more expensive than conventional methods, but significant efforts have been made to optimise this. (For example), our product range is competitively priced and has been meticulously engineered to meet the required performance benchmarks. 

“This is where government support becomes crucial—through policies and incentives that promote the use of sustainable materials, funding for innovation to drive research and testing of new building technologies, and industry-wide collaborative efforts,” she said. 

While Serina also said the lack of regulation and standardisation is a major impediment to fostering better industry practices that lower CO2 emission, she added that solutions other than relying on fly ash or GGBS are necessary to meet the demands for lower CO2 cement products, as buildings are going to continue to proliferate in developing countries.

“With a limited global supply of fly ash, simply incorporating mineral residues will not be sufficient in and of themselves to meet current and future demands for lower CO2 cement.  Alternative solutions will be necessary. 

“Some of these are already in development around the world.  One such technology is mineralised CO2 cement whereby injected CO2 undergoes a mineralisation process and becomes permanently embedded in the concrete. It shows improved CO2 reduction in the cement production,” Serina shared. 

Haddadian opines that the end users are often forgotten in discussions about the use of sustainable construction materials. 

“It is time for end users such as house buyers to put in the demand. Let's say they are going to rent or buy a new place, if they insist on the (greener) options, things will change a lot. I think it needs to come from them (the end users),” he emphasised.

Hannah said her company has made significant efforts to optimise lower CO2 cement products to address perceptions about cost and quality.

Fly ash is not any waste, it improves the building quality, said Haddadian.

Lack of regulation and standardisation a major impediment to fostering better industry practices, Serina said.

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