Testing Stage 1
The 1st stage of “Fibrearmering i betongelementer project” is monitoring changes of concrete properties due to the addition of dispersed reinforcement, steel fibers.
Tested were two mixes, which are standardly used for the production of precast wall elements, inner and outer walls. Two mixes in class B35 M45 and B45 M40 were tested with two different doses of steel fibers - 20 and 70 kg. Additionally, concrete mix B45 M40 was prepared with 40 kg of steel fibers per 1 m3. Dose 20 and 70 kg per 1 m3 was selected based on the NB38, which serves for establishing the sufficient fiber dose for given concrete. All mixes were prepared in laboratory conditions with the use of material supplied by Element NOR.
Fresh testing
Tested properties of fresh concrete are consistency, density, air content and fiber content.
Hardened concrete testing
Tested properties of hardened concrete consist of density, compressive strength after 10 hours and 28 days.
Summary of results and conclusion of the 1st stage
The 1st stage of the project consists of preparation and testing of 7 mixes with and without steel fibers. Aggregates were the only tested material from input materials, and the main focus was given to properties of fresh concrete and compressive strength of hardened concrete.