Kaolinitic clay for limestone calcined clay cement (LC3) in the United Arab Emirates

Swiss partners

• Ecole polytechnique fédérale de Lausanne EPFL: Karen Scrivener (main applicant), Eric Weber

Partners in the MENA region

• New York University Abu Dhabi, Emirats arabes unis: Kemal Celik (main applicant), Rotana Hay, Farah Shahbaz

Presentation of the projet

The project identified and assessed the properties and commercial viability of local and regional clays for LC³ implementation to contribute to decarbonizing the cement industry in the UAE. We focused on locating the potential clay sources and assessing their reactivity and composite performance. The major findings of the study are summarized below:

• A total of 9 kaolinitic clay samples were collected from cement and ceramic producers within the UAE.
• Eight of the 9 clays were characterized as low reactivity with kaolinite contents ranging between 4.0 and 17.7%.  
• Another clay sourced from Ibra, Oman, located approximately 450 km from the main cement-producing region of the UAE (Fujairah), exhibited a medium reactivity with a kaolinite content of 29.3%.
• Calcination at 800 ^oC almost completely decomposed the kaolinite phase in the clay samples.
• The calcined low-reactivity clays led to a noticeable strength reduction of the resulting LC³-based composites. When formulated with 40% replacement of ordinary Portland cement (OPC), the 3-day strength of LC³ was reduced by 29%. For LC³ with 3% hemihydrate, the reduction of strength was reduced to 12.3% at 90 days.          
• A comparable mechanical performance was achieved with the medium-reactivity clay.
• Life cycle assessment (LCA) revealed that despite the transportation distance from production facilities, the medium-reactivity clay from Ibra, Oman, resulted in LC³-based composites with 27 – 32% lower in CO₂ eq. emissions when normalized against 1-90 day strengths. 

More on this project

Article published in Cement and Concrete Composites (2022)

Article published in Construction and Building Materials (2023)

Second article published in Construction and Building Materials (2023)