Zero emission target set to be reached in Sweden by 2045 requires changes in many areas including also the construction industry with significant quantities of used building materials. The concrete, which is the most common material, is associated with emissions of large amounts of CO2 related to the Portland cement which is responsible for a total 5-8% of the global CO2. The Swedish concrete industry agreed to reduce the CO2 emission by half within next 5 years.
The amount of CO2 related to Portland cement can be reduced by its partial replacement with secondary binders; limestone, blast furnace slag or fly ash. Unfortunately, it may result in a slower strength development and worse durability of the produced concrete. Another, more extreme but also more efficient method is to fully replace the Portland cement with other type of CO2 neutral binders.
Changes that traditional concrete is forced into are problematic for contractors since there is not enough knowledge about ecological concrete performance. In our research group, several projects deal with investigation of different solutions to novel concrete problems.