MasterFiber 236 polypropylene macrofibres from Master Builders Solutions reinforce access roads and paved areas just as effectively as steel. This is the conclusion drawn by Fischer Kies + Beton AG, manufacturer and supplier of gravel and concrete in the Swiss Canton of Aargau. In addition, the fibres are lighter, easy to handle and definitely rust-free.
More durable roads built faster
Fischer Kies + Beton AG wanted to construct a new gravel production site, a gravel plant and a concrete plant. As a result, the company needed large areas for loading and unloading trucks and new access roads. The roads and loading areas were to be built from concrete in order to withstand the high loads expected.
Apart from cost, the key factor was durability. The roads and loading areas were to be used by trucks which can weigh as much as 60 t when fully loaded.
Starting with steel: first section of the project was completed with conventional steel reinforcement
The first paved areas in front of the new concrete plant were constructed using concrete with conventional steel reinforcement. 8 x 8 m slabs with steel reinforcement and broom finish were made from a G 330 concrete. In addition to these level surfaces, roads, in some cases with steep gradients, needed to be paved. The company, therefore, started to consider simpler, more cost-effective alternatives for construction.
MasterFiber 236: Synthetic fibres from Master Builders Solutions replace steel reinforcement
At this point, the concrete experts from Master Builders Solutions suggested MasterFiber 236: the polypropylene macrofibres reduce crack formation during the curing of concrete as well as drying shrinkage and stress development.
A fibre share of 0.1 percent by volume already reduces the total crack surface by between 30 and 40 percent. In addition, the fibres scarcely have any effect on the rheological properties of the fresh concrete. They can replace steel mats and have one fundamental advantage compared with steel reinforcement: as they cannot rust, the service life of the concrete element is significantly extended.
Installation of fibre-reinforced concrete with a paver
The Master Builders Solutions experts adapted the concrete formulation to allow installation using a paver. Apart from ensuring high resistance to freezing and thawing processes and a class C1 consistency, it was necessary to define the point in the mixing process where the fibres were to be added.
It was decided to add the fibres to the aggregate just before mixing in order to ensure optimum distribution within the concrete. In addition to MasterFiber 236, other Master Builders Solutions products used were the superplasticizer MasterGlenium SKY 652 to ensure optimum processing properties and MasterAir 302 air-entraining admixture to improve resistance to freezing and thawing processes.
Smooth completion following successful tests
The access road was concreted smoothly, without any difference from the use of conventional concrete. After compressive strength and bending tensile strength tests had been carried out on specimens produced especially for the purpose, the concrete was laid on site in two strips. The space between the two strips and the road edge towards the embankment was then concreted by hand. The application technicians from the Swiss Master Builders Solutions team provided support during construction and monitored the quality of the concrete. Seven days after the concrete had been laid, the heavy delivery trucks could already use the road.
MasterFiber performs convincingly throughout the project
Following this positive experience, the customer decided to stay with fibre-reinforced concrete. All in all, 2,540 square meters of concrete surface have now been paved using MasterFiber 236.
The advantages of MasterFiber macrofibres at a glance
There is no need for complex steel installation work, there is no additional wear on plants or equipment and there is no risk of injury caused by hard steel fibres. Finally, MasterFiber macro fibres do not rust – there is therefore no possibility of rust spots or hazardous progressive corrosion of the reinforcement in the concrete. Furthermore, polypropylene fibres are significantly lighter than steel and resist attack by alkalis and acids. In addition to these practical benefits, the performance capabilities of the fibres are convincing. They ensure a considerably higher resistance to subsequent cracking, reduce drying shrinkage and improve the fracture toughness of the concrete.
If you have any questions or inquiries, feel free to reach out to Jürgen. Additionally, you can find more information about MasterFibers from Master Builders Solutions on this page.
Jörgen Bokern
