5 th International Slag Valorisation Symposium | Leuven | 03-05/04/2017 243 UTILISATION OF ACTIVATED GGBS FOR NON- REINFORCED CONCRETE APPLICATIONS Ludovic ANDRE 1,2 , Laurent STEGER 1,2 , Diane ACHARD 3 , Laurent FROUIN 1 , Martin CYR 2 1 ECOCEM Materials Ltd., Paris, France 2 LMDC, Université de Toulouse, INSA, UPS, France 3 ECOCEM France SAS, Aix en Provence, France andre@insa-toulouse.fr, steger@insa-toulouse.fr, dachard@ecocem.fr, lau.frouin@gmail.com, cyr@insa-toulouse.fr Introduction Non-reinforced precast industry is a technical sector which uses low water-to-binder ratio, specific particular size distribution of aggregates, and needs high reactivity binders to ensure high production rates. The use of Supplementary Cementitious Materials is technically challenging in this industry but has benefits of reduced environmental impact and improved durability of the final products. A solution could be the partial replacement of Portland cement by ground granulated blast-furnace slag (GGBS) activated by several chemical compounds 1,2,3 . This paper aims to present the potential of GGBS to be used in non-reinforced concrete applications. The first part summarises the results of three industrial trials to produce blocks and curbs in precast plants with only limited amounts of GGBS and simple activation systems. The second part, realised at the laboratory scale with a specific and reproducible method developed to get close to dry concrete industrial process, aims to increase the GGBS content and to highlight the synergic effects of chemical activation and curing temperature. Materials and Methods The Portland cement used in all experiments and industrial trials was CEM I 52.5 conforming to European Standard NF EN 197-1 and GGBS conforming to NF EN 15167-1. Their specific surface areas (Blaine) were 4000 and 4400 cm 2 /g, respectively. A mixture of quartz sands (30% 0-2 mm and 70% 2-4 mm) was used in laboratory experiments. The chemical activation systems for GGBS used were based on different ways seen in literature: alkali (Na- and K-silicates, NaOH and KOH), alkali-sulfate (Na2SO4, with or without Ca(OH)2), chloride (NaCl, CaCl2), and chloride-sulfate (CaCl2, Na2SO4, anhydrite, gypsum). The laboratory program was carried out on 4x4x16 cm mortar bars with a control density of 1.95 T/m 3 , a realistic value in block industry. Binder content was 187 kg/m 3 (it was not possible to develop enough compaction energy to reduce it to 90-130 kg/m 3 , more realistic value for the industry) with a W/B of 0.4. A dry-mixed method was applied, where pre-homogenised materials were