Eco-blend cements for low-carbon construction

The document argues that eco-blend cements, which use industrial by-products like fly ash and slag to replace clinker, offer the most feasible near-term path to reducing the carbon footprint of South Africa's cement industry. It highlights that while these materials are abundant locally, regulatory caps on clinker substitution (currently 35%) and outdated structural standards act as primary barriers to wider adoption.

• Eco-blend cements have the potential to capture 90% of the South African cement market and could capture a portion of the estimated R496 billion intended for construction investment between 2013 and 2023.
• Increasing average clinker substitution levels by 5% (to an average of 35%) would result in emissions savings of over 450,000 tCO2e across the South African cement sector, which currently contributes approximately 1% of the country's total GHG emissions.
• South Africa possesses an abundance of SCMs due to its coal and steel industries, producing approximately 40 million tonnes of ash annually, though only 5% of this fly ash is currently used productively.
• Current South African regulations, specifically SANS 1197, limit clinker replacement to 35%, which the document identifies as a significant barrier to the commercial uptake of eco-blends.
• Local construction projects have successfully demonstrated clinker substitution levels far exceeding current regulations: the Portside building in Cape Town used up to 85%, Transnet’s City Deep Container Terminal used up to 100%, and the Loeriesfontein Wind Farm used up to 95%.
• Among various low-carbon technologies, eco-blends are considered the most feasible near-term alternative compared to Geopolymer cement (GPC), which has contested emissions reductions and safety risks, and Carbon Capture and Storage (CCS), which is capital intensive and speculative.

APA

Arp, R., Bole-Rentel, T., Gulati, M., Nkume, N., & Scholtz, L. (2018). Eco-blend cements for low-carbon construction. WWF South Africa. http://awsassets.wwf.org.za/downloads/wwf_2018_eco_blend_cements_for_low_carbon_construction_edit.pdf

Chicago

Arp, Reinhardt, Tjaša Bole-Rentel, Manisha Gulati, Nomahlubi Nkume, and Louise Scholtz. Eco-blend cements for low-carbon construction. WWF South Africa, 2018. http://awsassets.wwf.org.za/downloads/wwf_2018_eco_blend_cements_for_low_carbon_construction_edit.pdf.

Wikipedia

{{cite report |last1=Arp |first1=Reinhardt |last2=Bole-Rentel |first2=Tjaša |last3=Gulati |first3=Manisha |last4=Nkume |first4=Nomahlubi |last5=Scholtz |first5=Louise |title=Eco-blend cements for low-carbon construction |publisher=WWF South Africa |date=2018 |url=http://awsassets.wwf.org.za/downloads/wwf_2018_eco_blend_cements_for_low_carbon_construction_edit.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{arp2018ecoblend, author = {Arp, Reinhardt and Bole-Rentel, Tjaša and Gulati, Manisha and Nkume, Nomahlubi and Scholtz, Louise}, title = {{Eco-blend cements for low-carbon construction}}, institution = {WWF South Africa}, year = {2018}, url = {http://awsassets.wwf.org.za/downloads/wwf_2018_eco_blend_cements_for_low_carbon_construction_edit.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }