Limestone calcined clay cement

Definition

Combines clinker, calcined clay, limestone and gypsum, using synergistic hydration to reduce the clinker content of cement.

Material mechanism

LC3 does not simply add ordinary clay directly to cement. It combines the reactivity of calcined clay with synergistic reactions involving limestone. Specific formulations studied in research can reduce the clinker proportion to about half; this is not guaranteed for arbitrary combinations of raw materials.

Stages of development

Related research on calcined clay began around 2005, focused on ternary systems in 2009–2012, and entered international technical validation in 2014, followed by efforts toward industrial application. It is classified here as an emerging approach whose use is still expanding.

Principles and impact

Problems solved

Reduces demand for high-temperature clinker and its associated emissions while maintaining suitable performance.

Principles

Calcination activates kaolinitic clay, providing reactive silica and alumina components.
Activated clay and limestone work together to form hydration products, enabling a lower clinker proportion.

Improvements

Not recorded

Significance

Offers a low-clinker cement approach that can reuse parts of the existing manufacturing infrastructure.

History and applications

People

Karen Scrivener、Fernando Martirena

Organizations

EPFL、UCLV

Events

Not recorded

Applications

Low-clinker cement、Structural and nonstructural concrete in validated applications

Limitations

Clay quality, activation, grinding and mix proportions affect performance.
Emission reductions and performance benefits must be verified for the raw materials, plant and application conditions; a single percentage cannot be applied universally.

Upstream and downstream relations

Upstream

←CementspecializesLC3 is a blended cement approach that uses clinker, limestone, calcined clay, and gypsum.

Sources: The Material: Limestone Calcined Clay Cement

←Portland cementderived fromLC3 modifies the binder composition of a Portland clinker-based system, reducing the clinker proportion through the combined action of calcined clay and limestone.

Sources: The Material: Limestone Calcined Clay Cement LC3: a promising alternative

←Pozzolanic binder technologyderived fromLC3 uses the pozzolanic reactivity of activated clay together with synergistic reactions involving limestone. This is an application of a mechanism, not a historical claim that ancient Roman processes continued directly.

Sources: LC3: a promising alternative History LC3-Project

Downstream

→Concreteapplied inLC3 with verified performance can be used as a binder in concrete; its performance in use must be assessed in relation to the mix design and environment.

Sources: The Material: Limestone Calcined Clay Cement History LC3-Project

Sources for this entry and its relations

The Material: Limestone Calcined Clay Cement

Source: LC3 project / EPFL

Link: https://lc3.ch/the-material/

Accessed on: 2026-09-14

Evidence used here

LC3 consists of clinker, calcined clay, limestone, and gypsum. The alumina component in metakaolin works with limestone to form hydration products, allowing a higher degree of clinker substitution. Suitability depends on the clay's mineral composition and the actual properties of the materials.

History LC3-Project

Source: LC3 project / EPFL

Link: https://lc3.ch/history-of-lc3-research/

Accessed: 2026-09-14

Evidence used

Research in 2005–2008 examined calcined-clay pozzolanic materials; in 2009–2012 it shifted to ternary binding systems combining clay and limestone. The international technology validation phase began in 2014, followed by work on market adoption and large-scale production in 2017–2020. The start of research and the industrialization stages are presented separately.

LC3: a promising alternative

Source: Karen Scrivener et al., EPFL / Cementis; International Cement Review, July 2018

Link: https://lc3.ch/wp-content/uploads/2020/11/ICR30-KEYNOTE-EPFL-Limestone-Clay-cements.pdf