2.1 Materials¹

The cementitious materials used in all mixtures consisted of an ASTM C 150 Type I portland cement with a Blaine specific surface of 467 m²/kg and a density of 3050 kg/m³ and a ground granulated blast furnace slag. The two aggregates were a natural sand denoted "La Plata" and a coarse aggregate denoted "Brandywine". The sand had a maximum size of 3 mm and consisted of a mass fraction of 2.8 % of particles with dimensions smaller than 0.15 mm.

All admixtures used were commercially available products. All concrete mixtures incorporated a water−reducing and retarding admixture based on a sodium salt of organic acid mixture and with a specific gravity of 1.2. The high-range water-reducing admixture (HRWRA) was a polycarboxylate-based admixture with a specific gravity of 1.1. A viscosity modifying admixture was also used.

¹Certain commercial equipment, instruments, or materials are identified in this paper to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it implies that the materials or equipment identified are necessarily the best available for the purpose.