Kuraray recently registered its cement-reinforcing KURALON synthetic fiber under the Ministry of Land, Infrastructure, Transport and Tourism's New Technology Information System (NETIS)(*). Allocated the registration number CG-070010, there are plans to take this opportunity to actively develop this type of KURALON fiber—already widely used in public works and construction materials, which benefit from its special properties, such as superior adhesion to cement and high chemical and weather resistance levels—for other applications, such as air-blown slope surface mortar for public construction works.
Metallic lath (hole diameter φ2–50) is currently used as reinforcement material in air-blown slope surface mortar. However, unlike cast-concrete castings, there are disadvantages, as cracks caused by shrinkage when drying can easily develop due to, for example, the large surface area (wide and thin) and because of the difficulties associated with uniform curing (constant exposure to direct sunlight and the weather), as well as the direct influence of the ground (water, heat, geological features). The cost of repairs is also a major factor. Furthermore, construction work necessitates that traffic on roads in the immediate vicinity be regulated for an extended period of time, which has had an impact on people's everyday lives as well as on the environment.
KURALON (Product No. RFS400×18), which Kuraray developed in 2003 to have high tensile strength and to chemically bond to cement, achieves high crack resistance and improves freeze-thaw durability when mixed with mortar and air is blown across its surface. In addition, in cases where conventional methods such as metallic lath are omitted, KURALON also has the effect of shortening construction times as a result of the labor and manpower savings and reducing costs, while retaining the construction site's aesthetics.
Kuraray will endeavor to widely utilize cement-reinforcing KURALON's economic advantages and its ability to protect the living environment and improve conservation effectiveness, not only on newly formed but also on aging slope surfaces that are in need of repair.
More than 500,000m² on national highways and expressways using air-blown mortar from industrial waste disposal sites.
Price per m² at an air-blown thickness of 7cm ¥1,050
(At a recommended fiber loading of 10kg/m³)
In the first year after NETIS registration: 200 tons, ¥300 million
After three years: 500 tons, ¥750 million