product description:
Polyacrylonitrile fiber is a new type of reinforced fiber used in asphalt concrete or cement concrete to strengthen and prevent cracking. It is a synthetic fiber processed from polypropylene nitrile resin through a special process. The effect of mixing into cement concrete is similar to that of polypropylene fiber, and the role of mixing into asphalt concrete is roughly similar to that of polyester fiber.
Reinforcing effect of polyacrylonitrile fiber:
Polyacrylonitrile fibers are randomly distributed in three dimensions in mastic. These fibers can block the cracking of the mixture, thereby improving the self-healing ability of asphalt pavement cracks and reducing the appearance of cracks. However, it should be stated that not all fibers have this effect. Because the tensile strength of lignin fiber and mineral fiber is very low, they basically do not have the effect of reinforcement, while polypropylene nitrile fiber has higher strength, and the effect of reinforcement is more obvious.
Construction technology of polyacrylonitrile fiber asphalt concrete:
The requirements of polyacrylonitrile fibers on asphalt mixture are basically the same as those without adding fibers:
1. Before adding polyacrylonitrile fibers, first determine the mixing ratio of each tray of hot material bins, calculate the mass of each tray of mixed material, and then pack the incoming fibers according to this mass. If the mixing volume of each plate is 3 tons, the mixing volume is 2%. Carry out the calculation, that is, the dosage is 6kg
2. The asphalt mixture should be trial-mixed according to the designed amount of asphalt. After the trial mixing, samples should be taken for Marshall test, and the test value should be compared with the test results of the mixing ratio in the laboratory to verify the rationality of the designed asphalt amount, and make appropriate adjustments if necessary.
3. Determine the appropriate mixing time, extend the dry mixing time with the aggregate for 15-30 seconds, and then add asphalt for wet mixing. Finally, the mixture is evenly mixed and the fiber and asphalt mixture are well coated.
4. For traditional continuous mixing equipment, it is necessary to add special fiber adding equipment. Since the proportion of fiber in the mixture is very small, the accuracy of the equipment will affect the unevenness of the amount of fiber added. Therefore, the traditional intermittent mixing equipment adopts manual feeding of fibers, which is economical and convenient.
5. The compaction procedure is basically the same as that of ordinary asphalt mixture, which is divided into initial pressure, re-pressure and final pressure. However, due to the increase in the viscosity of the asphalt mixture after adding fibers, it should be compacted 1-2 times on the basis of ordinary mixture rolling.
Construction technology of polyacrylonitrile fiber in cement concrete:
1. Determine the amount of fiber input according to the amount of concrete.
2. Prepare sand and gravel, add fiber, dry mix for 30-45S, add cement and water, mix for about 30S to ensure that the fiber is evenly dispersed.
3. Take samples after mixing. If the fibers are evenly dispersed, the concrete can be put into use. If there are bundled monofilaments, you need to prolong the mixing time for 25-30S
4.The construction and maintenance process of adding polyacrylonitrile fiber is exactly the same as that of ordinary concrete
Post time: Jul-24-2023