Over the past ten years the technology adding fibers in concrete has gained enormous popularity. Such recognition must: a) persistent actions on the organization and sales promotion undertaken by producers of fibers and their distributors and b) the most recent data on the independent technical tests. Not only the engineering and materials science disciplines, offering the use of fiber in concrete, but also producers and professionals demonstrate the success of fiber reinforced concrete on the spot. Reputation reliable: fibers reduce cracking during shrinkage. Use of fiber reinforced concrete, dates back to the construction of the Colosseum of Rome, however, it took several years to conduct serious research to make this technology widespread. In today's concrete industry fibers can be divided into two major groups: steel and synthetic. Steel fibers have a very specific use and are generally not used in conventional concrete slabs, pavements, floors. Steel fibers are added to concrete, if you want high strength for blow. Concrete floors are subjected to the stresses of the working environment (for example, automobile assembly shop). In these cases, the use of steel fibers can be justified. Steel fiber will help reduce the cracking of concrete for shrinkage, as well as synthetic fibers, steel fibers but not often used to protect against cracking during shrinkage. Steel fibers are of various sizes and configurations. The most common wavy fiber length of 40 - 50 mm and a diameter of about one mm. Dosage of fibers per cubic meter ranges from 15 to 45 kg. Synthetic fibers are made of polypropylene, nylon or fiberglass. Polypropylene and nylon fibers, tend to be more convenient for concrete workers in the performance of concrete work. Nylon and polypropylene fibers are used more widely. In connection with this fiberglass fades into the background, and its use is declining. Although first glance, it seems difficult to distinguish one type of synthetic fibers from each other, and they, like, should work the same way. Synthetic fibers, as well as steel, come in different shapes and sizes. They differ in characteristics such as denier (fineness), the number of fibers (the number of individual fibers per unit area) and the tensile strength (resistance to stretch). Most concrete producers and their customers prefer different types of fibers. In slabs, pavements and sidewalks are most commonly used fiber length 6-12 mm. Dosage fibers with ranges from 0.6 kg to 2.0 kg per cubic meter of concrete. Fresh brewed concrete undergoes a number of different chemical transformations. The chemical process of transition from a liquid concrete (ductile) to a solid state is accompanied by heat. Although it is warm and it is important to increase the strength at an early stage, it can also have a negative impact on the concrete and cause its expansion. As the concrete hardens, the maximum temperature reached. Reaching an extremum, the concrete begins to cool slowly. Thus it is compressed or shrink. This change in volume can create stress in the concrete, which can lead to thermal cracking. Forming a cohesive framework, fiber helps to avoid this effect. Plastic shrinkage cracks formation is different from the thermal cracking of the fact that it has more to do with humidity than with inner warmth. Weather conditions can dry the concrete surface even before it is reached the initial state of hardening. At the same time within the concrete can retain its plasticity, while its surface can be completely dehydrated. Excessive loss of moisture on the surface can lead to a false setting and the effect of shrinkage. The similarity between the thermal cracking and the formation of plastic shrinkage cracks is that both of these effects are caused by a change in volume of concrete. The difference also lies in the causes of this change. Reinforcement fibers, in most cases, should not be considered as an alternative to steel reinforcement. Reinforcement fibers, however, must be regarded as an event that can significantly reduce the possibility of formation of plastic shrinkage cracks and can help minimize the effects of thermal cracking. Cracks on the concrete surface contribute to the penetration of water and chemicals. Many forms of chemical and physical destruction can begin their advance through the surface cracks, which affect the durability and service life of concrete. In addition, surface cracks can not be aesthetically appealing. Use of concrete reinforcement fibers is an economical approach, minimizing the formation of plastic shrinkage cracks that reduce the thermal cracking and increasing the durability of concrete.