Basalt fiber
Basalt Fiber (BF) is a continuous fiber made of pure natural basalt material, crushed and added to the furnace, melted at a high temperature of 1450 ℃ ~ 1500 ℃, and drawn through a platinum rhodium alloy wire drawing plate at high speed . The diameter of basalt fiber produced by the existing process can reach 6~13μm, which is thinner than the hair.
During World War II, basalt fiber technology was vigorously developed by the United States, Europe and the former Soviet Union, and was widely used in the military and aerospace fields. In 1995, with the technology decryption, basalt fiber technology was greatly promoted in the civilian field.
Basalt fiber applications
Basalt fiber is now one of the four major fibers (basalt fiber, carbon fiber, aramid, ultra-high molecular weight polyethylene fiber) developed in China, and various products prepared from it are widely used in defense military industry, aerospace, fire protection , Environmental protection, vehicle and ship manufacturing, petrochemical, power electronics, sports, medical and civil engineering and other fields.
Basalt fiber products
This article will briefly introduce some applications of basalt fiber and summarize the application of basalt fiber in the field of road engineering.
Stealth
Basalt fiber has the characteristics of high strength and high and low temperature resistance, which is very in line with the requirements of the surface materials of aircraft and missiles. At the same time, it has the characteristics of wave absorption and magnetic permeability, which can achieve radar stealth. Therefore, basalt carbon fiber can partially replace carbon fiber for stealth aircraft and missiles.
bulletproof
At present, ultra-high molecular weight polyethylene fibers are usually used for bulletproof vests, which have low heat resistance, and the strength and modulus will be reduced under high temperature melting of the bullet, which will affect the bulletproof effect. In contrast, basalt fiber has a high temperature resistance, so this problem does not exist.
Aerospace
Basalt fiber has low thermal conductivity and good flame retardant performance. The operating temperature range is -269℃~700℃, which is resistant to both high and low temperatures. To meet the stringent requirements for materials in the aerospace field, most of Russia's aerospace materials are made of this material.
Application in the field of road engineering
Basalt fiber has the advantages of high tensile strength, good mechanical properties, high temperature resistance, UV protection, acid resistance, alkali resistance, salt resistance, and aging resistance. Compared with other fibers, its comprehensive performance is better, and it also meets the requirements for materials in the field of road engineering. Therefore, in recent years, more and more basalt fiber products have been used in road engineering.
The basalt fiber is made into a mesh base material through a warp knitting process, and the basalt fiber geogrid can be made through surface coating treatment. Basalt geogrids are commonly used to reinforce asphalt roads, strengthen subgrades and soft soil foundations.
Basalt fiber geogrid used in asphalt pavement reinforcement has the following advantages:
Meet construction temperature requirements
When paving the mixture, the geogrid needs to withstand a high temperature of 100 ℃ ~ 200 ℃, the working temperature of basalt fiber can reach 700 ℃, so its performance will not be affected by high temperature.
Strong durability
The basalt fiber geogrid can resist all kinds of physical wear and chemical erosion, and has strong anti-aging properties. In addition, the basalt fiber deforms very little under long-term load and can maintain its performance for a long time.
Improve the performance of asphalt pavement.
The basalt geotechnical fiber grid disperses the wheel load stress in the asphalt surface layer to reduce stress concentration, and at the same time, its own deformation is small, which can reduce the road surface deflection to a certain extent, thereby improving fatigue performance.
Road crack
In addition, the geogrid can limit the movement of the aggregate in the mixture and improve the high-temperature deformation resistance of the pavement; under low temperature conditions in winter, the geogrid can offset the tensile stress of the asphalt surface layer, reduce the occurrence of shrinkage and reflection cracks, and improve the pavement. Low temperature resistance.
Chopped basalt fiber
Chopped basalt fiber can be used for asphalt mixture, cement concrete and crushed stone seal.
Asphalt
At present, lignin fiber, polyester fiber and some mineral wool fiber are mainly used in asphalt mixture. Among them, lignin fiber is not resistant to high temperature, and its tensile strength is very low. Polyester fiber has poor compatibility with the mixture and poor high temperature resistance. Mineral wool fiber is harmful to the human body, and easy to clump.
The use of basalt fiber instead of the above-mentioned fiber to prepare asphalt mixture can not only overcome the above shortcomings, but also enhance the road performance of the mixture.
BS
Basalt fiber is silicate fiber, which is easy to disperse when mixed with cement concrete and mortar, has good compatibility, and the mixed fiber concrete is stable. And the basalt fiber has good durability and high strength. Adding to cement concrete can increase the strength of cement concrete, reduce cracks and improve durability.
Gravel seal
The basalt fiber sealing technology is to spread asphalt binder and basalt fiber first, then spread crushed stone on top, and then form a new wear layer after rolling. The basalt fibers are evenly distributed in the asphalt mixture, overlap each other, and form a network structure with the mixture, which can improve the abrasion resistance of the seal layer and the tensile, shear, compressive and impact strength.
Basalt fiber composite bars
Basalt fiber composite bars are mainly used for cement concrete pavement in the field of road engineering. It has the following advantages.
Good binding with cement
The physical and chemical properties of basalt fiber composite bars are similar to cement, with good adhesion, and consistent with the thermal expansion and contraction coefficient of cement.
preservative
Compared with reinforced steel, basalt fiber is more durable and can improve the durability of pavement.