Since the 1980s, the US chemical industry production of synthetic materials, a filament (called FIBERMESH), and applied to concrete buildings, through a lot of material properties and test engineering structures, has been widely used. Early tensile strength of reinforced concrete to prevent intrinsic microcracks early by subsidence, heat of hydration, shrinkage and produce, reducing the performance of cracks and crack width, reinforced concrete seepage performance, impact resistance and abrasion resistance enhancing the overall structure nature has a distinct role. Now for a brief introduction to the main performance fiber reinforced concrete and scope.

1. The non-structural cracks in concrete
    Concrete cracks, has long been considered a normal phenomenon, and think does not affect its use. When the stress exceeds the strength of the concrete cracks appeared. Cracks generated by external stress caused usable improve concrete paving, structural strength Wall structure to compensate. However, the intrinsic stress caused by shrinkage of concrete itself has long been an issue to be added to control. As these types of unforeseen cracks, location and mechanism of their occurrence, the vast majority of its intrinsic stress cracks due to shrinkage caused by the drying process produces. These cracks are formed in the first 24h after concreting. Subsidence and contraction cracks in the initial period of time can not be observed, they often wipe the surface of the light on the surface of bridge, or just not wide enough and you do not see until the concrete cracks due to loads of these weak surface microcracks develop into visible cracks.

    Plastic shrinkage cracks generally throughout the member or plate, the concrete and reduce its overall reach its design strength before the formation of the weak side.

Synthetic fibers are added to concrete in concrete composite material made of polypropylene filaments, in order to enhance tensile strength plastic concrete, significantly reduced their plastic flow and shrinkage microcracks. Such reduction or elimination of plastic cracking of the concrete to get its best long-term integrity. Composites made of polypropylene filaments are specially designed and developed products used in concrete, which is made of fiber bundles. When the fiber bundle dosage 0.9 kg / m3 concrete mix is ​​added by mixing it open and dispersed into numerous individual fibers. These fibers were evenly distributed throughout all the concrete, the concrete reinforcement to get aid to prevent shrinkage cracks. Fibers are everywhere in concrete, the concrete may also occur in minimizing an intensity state crack width and length.

    Join polypropylene fiber concrete can reduce their total bleeding rate and increased elongation plastic concrete, thereby doubling the role of anti-plastic subsidence cracks.

2. Reinforcement of modern microscopic techniques
    To avoid cracks in the concrete surface, often used steel wire mesh, which is always worried about their position is correct or has moved to increase the difficulty of construction. The current development of polypropylene fiber reinforced concrete, is an extremely high level of plasticity in the concrete hardening process and its reinforcement of modern technology.

    Comparison with steel mesh reinforcement, fiber reinforced concrete in addition to preventing cracks concentrated, there on the concrete reinforcement to prevent plastic shrinkage cracks, strengthen impact, abrasion resistance, resistance to breakage, with rust corrosion and safety , ease of use. Another fiber reinforced concrete without using cranes, steel wire and other fixed equipment, which can speed up the construction schedule, saving construction costs.

    Synthetic filament material is an inert material, does not affect the molding properties of concrete, it can adapt to a variety of surface treatment processes such as compaction molding, hand wiping spatula crowded, dynamic wiping pressure, surface coating, coloring, dry brush, adding liquid as early as tough agent and aerated agent.

    Fiber concrete surface will not rust and rust stains, synthetic yarn and non-corrosive acid. Under normal viscous fiber content of fresh concrete workability vibration that is good, is not affected by the addition of fiber and its workability. Chemical hydrolysis of fiber cement does not have any impact, it is completely pure mechanical action to improve their working and mechanical properties. Previously added fiber factory in the center of the concrete or concrete mixing truck required mixing time and speed after discharging fibers can be evenly distributed in the concrete, it will not change its agitation over job performance.

3. tow - Advanced Concrete Technology
    US production of synthetic materials tow company FIBERMESH implement a continuous worldwide research program to promote fiber bundle for concrete structures, research in some famous universities and research institutions are: plastic cracks, impact testing, scratch bending strength, static load test strength, durability, shotcrete, chloride penetration, steel corrosion, fatigue strength, abrasion resistance, tensile stress and strain, rheological properties, crack width, bonding properties, compressive strength test subject, Bleeding, seismic testing, frost resistance, consistency, petroleum reaction, durability level.

    Fiber bundle is designed for the development of new synthetic materials produced concrete products. Synthetic materials industry and concrete technical engineers work closely to develop a new type of concrete, mortar, mortar and pouring products, research and production, which is a synthetic material provides a reliable technical guarantee in the concrete industry applications. According to experimental research and practical application, fiber reinforced concrete has the following advantages.

3.1 reduce the permeability of plastic and concrete cracks
    Tests showed that adding fiber composite materials concrete, concrete significantly increased the ability of the early anti-shrinkage cracks and vibration caused by cracks. Added in an amount of 0.9kg / m3 of polypropylene fibers increases the anti-