Concrete Performance of Limestone Calcined Clay Cement (LC3) Compared with Conventional Cements

This study aims to demonstrate the robustness of concrete made of limestone calcined clay cement (LC3). Two campaigns were carried out using 375 kg.m(-3) and 500 kg.m(-3) of binder and targeting plastic and self-placing workability, respectively. The concrete performance of LC3 was compared with plain portland cement (PC), slag cement, and a blend containing silica fume. The density of concrete was found very similar between the different types of binders. The amount of superplasticizer required to reach the workability criteria was higher for the blend with silica fume compared with LC3. Moreover, the increase of workability required the same increment of superplasticizer, independent on the type of binder. In terms of strength, 57.2 MPa and 72.3 MPa were reached at 28 days for LC3 for the first and for the second campaign. Similar strength to PC is obtained for LC3 for all ages for the first campaign, outperforming slag concrete. For the second campaign, similar strength to PC is reached at 7 days. Very low absorption and resistance to freeze-thaw with deicing salt were measured. The air permeability was found lower for LC3 than PC. CO2 emissions per unit strength are significantly reduced for LC3 compared with PC, and with other blends for the first campaign.