Mineral powder concrete – effects of powder content on concrete properties

The effects of partial replacement of Portland cement with non-pozzolanic mineral powders on normal-strength concretes were studied. The observed concrete properties were workability, pumpability, compressive strength and microstructure. Superplasticisers were used in every test concrete. With the addition of mineral powders, the water requirement of the concrete mixes decreased and the compressive strength of the mineral powder concretes was kept at the same level as in a reference mix by using on average a 75 kg/m³ lower cement amount. Studies of the microstructure of the concretes were made using resin-impregnated and polished specimens that were prepared from three concretes, each containing a different mineral powder. In the environmental scanning electron microscopy study, the specimens showed densification of the interfacial transition zone when mineral powders were used. The effects of the mineral powders on the workability, water requirement and compressive strength values of the concretes were evaluated in relation to grading curves.