LC3: a promising alternative
The drive for a sustainable construction industry has triggered the development of a range of building materials that serve as sustainable alternatives to Portland cement. The development of limestone calcined clay cements (LC3) offers a glimpse into the future of building materials. By Karen Scrivener, Franco Zunino, François Avet and Wilasinee Hangpongpun, EPFL STI IMX LMC, Switzerland, and Anne Dekeukelaere and Laurent Grimmeissen, Cementis Consulting, Switzerland.
Figure 1: SE micrograph of a kaolinitic clay particle showing the layered structure
Limestone and calcined clays are unique among supplementary cementitious materials (SCMs), as they not only offer good properties when used in combination with cement, but are also available in effectively unlimited quantities.1 Limestone calcined clay cements (LC3) are blended cements that combine clinker, limestone, calcined clay and gypsum. They take advantage of the high reactivity of calcined clay and the synergic reaction between limestone and clay, offering equivalent mechanical performance to normal Portland cement (CEM I/OPC) with clinker factors down to 50 per cent.
