Polypropylene fibers added to concrete, whether or not combined with reinforcement, are aimed at making the concrete better. That is why they are used in many construction works where concrete has an important role to play.
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Polypropylene fibers prevent cracks from developing during the concrete curing phase (= plastic phase). The curing phase, which takes place during the first 24 hours, is crucial for the concrete’s later characteristics. Polypropylene fibers prevent micro-cracks in the plastic phase. This in turn prevents the formation of macro-cracks during a later phase.
PP fibers enhance the cohesiveness of the mix and prevent segregation of the mix during casting. A more cohesive mix will also result in a faster demoulding of the precast elements, resulting in significant time gains.
Polypropylene fibers improve early-age compressive strength by bridging microcracks, reducing shrinkage, and promoting a denser, more uniform cement matrix. This reinforcement helps concrete gain strength faster while maintaining structural integrity during its critical curing phase.
Polypropylene fibers will make concrete bleed less. During compacting/vibrating or floating concrete, water will rise to the surface and seek its way out. This is referred to as “bleeding”. Polypropylene fibers will make sure that water finds its way out less easily.
Due to bleeding, water rises and accumulates at the surface. Sometimes, along with this water, a certain amount of cement also rises to the surface. When the surface is worked up with the trowel, the aggregate goes down and the cement and water rise to the surface. With the evaporation of water, the accumulated fine material will develop cracks and plastic shrinkage. As a result, it will affect the concrete quality. More specifically, strength will be reduced, the bonding between two successive layers will be poor and wear resistance will be reduced.
Why?
This will result in:
Polypropylene fibres make concrete last longer by increasing its resistance to microcracking and abrasion, which strengthens the surface against wear over time. These fibres form a fine network within the matrix that reduces segregation and bleeding, leading to a denser, more durable surface. By limiting early-age shrinkage and stabilizing the paste, they minimize weak zones that can break down into dust under traffic or environmental exposure. As a result, concrete treated with micro polypropylene fibres maintains its integrity and appearance for longer, while significantly reducing surface dusting.
PP fibers in shotcrete for tunnels, walls, etc. … will make sure that concrete will rebound less. Traditional concrete will always have material bouncing back, as a result of spraying against a wall. PP fibers will reduce that mountain of waste and make sure you will loose less concrete during concrete spraying.
PP fibers in shotcrete for tunnels, walls, etc. … will make sure that concrete will rebound less. Traditional concrete will always have material bouncing back, as a result of spraying against a wall. PP fibers will reduce that mountain of waste and make sure you will loose less concrete during concrete spraying.
PP fibers in shotcrete for tunnels, walls, etc. … will make sure that concrete will rebound less. Traditional concrete will always have material bouncing back, as a result of spraying against a wall. PP fibers will reduce that mountain of waste and make sure you will loose less concrete during concrete spraying.
Polypropylene fibres help resist corrosion in concrete by being chemically inert and highly resistant to alkalis present in cement paste. Unlike steel fibres, they do not rust or degrade when exposed to moisture or alkaline environments, ensuring long-term stability.
Freeze-thaw damage will occur when water residing in the concrete is freezing. The water will expand, which will lead to crack formation and scaling off. That is why it is necessary to use freeze-thaw resistant concrete for structures that are subject to this process. Polypropylene fibers will reduce or even stop this process and will give the concrete a better resistance to freezing and thawing cycles.
Polypropylene fibres improve water migration in concrete by blocking bleed water channels and stabilizing particle movement, which reduces the rate and capacity of bleeding. This creates a more homogeneous mix, limiting the upward flow of water and minimizing plastic settlement. By forming a fine filament matrix within the fresh concrete, the fibres disrupt continuous capillary pathways, thereby slowing water migration to the surface. As a result, the concrete experiences less plastic shrinkage cracking and improved durability in its early stages.
Polypropylene fibres help prevent concrete element damage during transportation by enhancing the material’s toughness and resistance to microcracking. These fine fibres form a three-dimensional network within the concrete matrix, bridging microcracks and distributing stresses more evenly. This reduces the risk of surface spalling, edge chipping, and impact-related fractures that often occur during handling and transit.
Polypropylene fibers in concrete present significant improvements in terms of fire resistance and reduction of spall damage.
Polypropylene fibers in concrete will make sure that steam resulting from a fire finds an outlet quickly. The water in the concrete will start to steam. This steam is very powerful and literally makes pieces break off the concrete. Polypropylene fibers will melt at 140°C and form millions of small channels along which steam can escape. Polypropylene fibers prevent concrete spalling, which means that the fire will not reach the rebars or any of the critical components that could make the construction collapse. This time gain can be of vital importance in tunnels. Polypropylene fibers will also make sure that less repair work is needed afterwards.
Polypropylene fibers will provide: