Calcined clay tackling carbon embodied in construction

Briefing paper from Mission Possible Partnership and Systemiq, with support from HSBC, highlights the commercial opportunity found in replacing clinker with limestone calcined clay in cement production.

This material has the potential to be a critical component in achieving fast emission reductions in this sector and comes with clear benefits:

• Cost reductions: Replacing clinker with limestone calcined clay reduces energy costs by over 33% compared to ordinary Portland Cement and reduces CO₂ emissions by a minimum of 40%
• Commercially proven: Infrastructure projects worldwide — including Colombia, Switzerland and Brazil — already use calcined clay cement, demonstrating proven performance and scalability. It is also already embedded in international cement standards
• Widely available: Compared to other Supplementary Cementitious Materials such as ground granulated blast-furnace slag and fly ash, calcined clay is more abundant and less subject to declining availability or rising costs
• High performance: Calcined clay-based cement mixtures offer similar strength and durability to alternatives and are suitable for use in harsh environments
• A drop-in solution: It is compatible with traditional clinker and suitable for processing in existing clinker kilns – allowing efficient use of current assets and making it a future aligned investment

Context

This briefing paper is part of Mission Possible Partnership’s broader effort to accelerate low-carbon construction materials. Specifically, this initiative explored opportunities to accelerate the production and consumption of calcined clay in Türkiye, the UAE and Saudi Arabia as a critical material to achieve fast emission reduction in the cement and concrete sector.

It outlines key insights from 60+ bilateral conversations (held from October 2024 to May 2025) and a meeting on May 9th 2025 in Lausanne, hosted by the LC3 Project, MPP and Systemiq – with philanthropic support from HSBC.

The initiative aims to pinpoint critical actions and engage pioneering stakeholders to turn momentum into real deployment of calcined clay-based cement, whether through collective or independent action.

Objectives

1. Describe the opportunity and objectives behind calcined clay’ as a low-carbon cement solution
2. Provide insights on how to accelerate the production of and demand for calcined clay
3. Share a focused Call to Action to drive this further, through 5 clear initiatives

Read | Calcined clay briefing