Unique tests with hybrid reinforced concrete
Together with its project partners Bruil, Mertens Bouwbedrijf, Metalproducts BV, Schipper Vloeren, M2i (Materials innovation institute) and the TU Eindhoven, ABT is currently performing large-scale tests of hybrid reinforced concrete.
Hybrid reinforced concrete combines the strengths of steel fibre with traditional reinforcement. Sixty beams are being tested in the laboratories of TU Eindhoven, half of them with a length of 6.2 meters, the other half with a length of 3.2 meters. The width of the beams is 300 mm, the height 300 or 600 mm. On the beams with a length of 6.2 meters, a three-point bending test will be performed. The beams with a length of 3.4 meters will tested for shear resistance, as illustrated in the figure below.
Test set-up shear test
At this time only limited standards are available for hybrid reinforced concrete. Over the past years, ABT has developed and validated a calculation model, which materialized in a Dutch CUR-aanbeveling 111: steel fibre reinforced industrial floors on poles. This recommendation is only aimed at a narrow range of applications.
The large-scale tests that are being carried out have been set up for a wider applicability of the calculation model. The aim of this activity is to achieve regulations on a European level. Tests start in September and last for three months.
Hybrid reinforced constructions are not yet widely accepted by municipalities, concrete plants and contractors. Due to the specialized designs, municipalities cannot easily check if the design meets standards and legislation. Concrete plants sometimes lack knowledge about fibres and the equipment to mix fibres and concrete. Contractors are not familiar with fibres, either. ABT wants to change that.