Development of eco ultra‐high performance concrete for the prefabrication of ultra‐thin concrete shells

Abstract The present study focuses on the development of an eco‐UHPC to be used in a prefabrication company to produce ultra‐thin concrete shells. The composition targeted a strong (up to 50%) reduction of the Portland cement content, with a partial replacement of the latter by different cementitious additions, combined with limestone filler. The studied parameters also included the type and dosage of the reinforcing fibers and the size and type (natural or lightweight) of the aggregates. In this scope, different eco‐UHPCs were produced and characterized, considering both mechanical and durability properties. Different additions proved to have a high pozzolanic effect, especially at older ages, being therefore a good option for producing UHPCs with the required performance and the desired low cement content. In addition, the developed eco‐UHPCs exhibited extraordinary durability, with very reduced capillary absorption, absence of carbonation, and high resistance to chloride migration.