France – Research and experimental development services – Développement de formulations de matériaux cimentaires à base de ciments bas carbone

In the context of conditioning low and medium activity short-lived (LILW-SL) waste, the main waste producers, such as the CEA, EDF and Orano, as well as the Andra, use cementitious materials (grout, mortars, concretes) to manufacture storage packages and structures. To date, the Centre de Stockage de l’Aube (CSA) reference framework only authorises the use of CEM I, CEM III and CEM V type cements. However, the evolution of the civil engineering sector, notably due to the challenges of the ecological transition, is driving significant changes in the cement industry. In particular, a progressive reduction in the production of certain traditional cements is anticipated by the 2030s, due to environmental constraints (CO2 emissions linked to clinker) and the limited availability of certain raw materials. The aim is to develop and qualify new formulations of cementitious materials and to integrate innovative solutions, such as low-carbon cements. The objective of the service is to develop 12 formulations of low-carbon cement-based materials. Based on a pre-identified list of cements, 4 low-carbon cements will be selected and used to develop formulations of 3 types of materials: mortars, reinforced concretes and fibre-reinforced concretes. The service is carried out in 3 stages:

• Stage 1: Characterisation of low-carbon cements:

- Tests on powders,

- Tests on pastes and standardised mortars; to select the cements to be retained for the rest of the study

• Stage 2: Selection of admixtures

Inventory of admixtures that could be used with the identified low-carbon cements:

- Tests to select the admixtures that will be included in the composition of the formulations

• Stage 3: Development of cementitious material formulations:

- Development at laboratory scale,

- Suitability tests.

Given the sustainability of their supply, it is agreed to exclude from this study low-carbon cements incorporating industrial by-products such as blast furnace slag and fly ash. The low-carbon cements selected are therefore those composed of clinker (K), natural pozzolans (P) or calcined natural pozzolans (Q) and/or limestone (LL).