Glass fiber geogrid can be used to reinforce the pavement
Author: Hengke Shandong HuaSu Engineering Co., Ltd Time: 2020-02-10 07:55 Visits: second
Description: fiberglass geogrids act on subgrade reinforcement and prevent reflective cracks through two important mechanisms: direct tensile stress and lateral displacement of confined soil. For the asphalt concrete added with glass fiber geogrid, the mesh structure of glass fiber geogrid makes the glass fiber geogrid play a role of reinforcing the asphalt mixture in the mesh. Therefore, when the foundation at the bottom of asphalt concrete structure layer under the action of load, cracks appear and extend to the glass fiber geogrid.
? Glass fiber geogrid It is used in road structural layer, mainly for anti fatigue cracking, subgrade reinforcement and anti reflection crack, and its mechanism is as follows:
(1) Mechanism of anti fatigue cracking
Asphalt pavement must have a certain bearing capacity, and fatigue failure can not occur in the specified time. The asphalt pavement is under pressure at the lower layer directly in contact with the wheel, and it is subject to tensile force in the area outside the wheel load edge. Because the stress properties of the two stress areas are different and close to each other, the failure occurs at the junction of the two stress areas, and fatigue cracking occurs under the long-term load. ?
The glass fiber geogrid can disperse the above-mentioned compressive stress and tensile stress in the asphalt surface layer, and form a buffer belt between the two stress areas, thus reducing the damage of the asphalt surface layer caused by stress mutation. At the same time, the low elongation of the glass fiber geogrid reduces the deflection of the pavement and ensures that the pavement will not be excessively deformed. ??
(2) Mechanism of subgrade reinforcement and reflection crack prevention
Glass fiber geogrid acts on subgrade reinforcement and prevents reflective cracks through two important mechanisms: direct tensile stress and lateral displacement of soil. For the asphalt concrete added with glass fiber geogrid, the mesh structure of glass fiber geogrid makes the glass fiber geogrid play a role of reinforcing the asphalt mixture in the mesh. Therefore, when cracks appear in the foundation at the bottom of asphalt concrete structure layer and extend to the glass fiber geogrid under the action of load, the existence of geogrid changes the stress condition of crack tip, and limits the opening deformation of crack, so as to strengthen the subgrade and inhibit the upward development of cracks. ?
The stability of the mesh structure of glass fiber geogrid is strengthened by filling with asphalt mixture. The high tensile strength of glass fiber geogrid is the main factor to restrain the opening deformation. The asphalt concrete added with glass fiber geogrid can effectively improve the stress distribution of pavement structure, resist and delay the occurrence of pavement diseases caused by subgrade cracks, so that the asphalt concrete structural layer will not be damaged due to tension deformation for a long time. Compared with the asphalt concrete structure layer without glass fiber geogrid, the use of glass fiber geogrid can be larger Greatly improve the service life of pavement. ?
In China, the application of fiberglass geogrid is relatively late. In the construction of Shanghai Nanjing Expressway from 1995 to 1996, glass fiber geogrid was mainly used in asphalt pavement to avoid the reflection cracks of asphalt surface caused by cracks in the surface and bottom layer. After years of inquiry, the effect is remarkable. Therefore, in the repair project of Shanghai Nanjing Expressway from 1997 to 2002, the glass fiber geogrid is still used The HDPE of steel plastic geogrid can ensure that it will not be corroded by acid, alkali and salt solution or oil at normal temperature, and will not be damaged by water dissolution or microorganism. Together, the polymer function of polyethylene is enough to resist the aging caused by ultraviolet radiation. After the geogrid is stressed, the longitudinal and horizontal ribs will cooperate, and the nodes will not be cracked or damaged. In the practice project, after compaction, the filling material is not corroded by ultraviolet light and oxygen, so it can completely satisfy the requirements of permanent engineering