Cold recycling techniques are known for decades in pavement engineering as a suitable rehabilitation method mainly for existing asphalt pavements. Traditionally the most common solution is to use bituminous emulsion or foamed bitumen as a binder usually in combination with small amount of cement or lime as active fillers. In some countries cement or hydraulic road binders are preferred instead of bitumen based options since it is believed that hydraulic binders can increase the bearing capacity of cold recycled layer especially for pavements with underestimated structures which were designed >40 years ago. Based on that the Faculty of Civil Engineering, CTU Prague is for more than 10 years evaluating and developing further alternatives for the cement-based approach of cold recycled mixtures. In the past experience with fly-ashes or activated fly-ash based alternative binders were presented. Presently the focus is concentrating on the potentials of using blast furnace slags which are not generally usable for the cement industry (e.g. because of limited content of glassy compounds which are very typical mainly for granulated blast furnace slags). Air-cooled blast furnace slags were selected and activated by high-speed milling to get a material with latent hydraulic properties. This modified slag was applied in several options to cold recycled mixtures and standard strength and deformation tests were performed, including the determination of resistance to water immersion. Separately pastes based on used treated fine-grained slags were tested and evaluated. Data of the pastes are discussed jointly with the results for experimentally tested cold recycled mixtures.