Application of Glass Fiber Geogrid in Asphalt Pavement Construction
Abstract: In order to solve the problem of asphalt pavement damage caused by vehicle load, based on the construction practice of an asphalt concrete pavement of a highway, the basic functions and construction methods of the glass fiber wholesale uniaxial plastic geogrid are added by adding a glass fiber uniaxial plastic geogrid for sale to the asphalt pavement structure. The system was introduced in terms of construction technology and the response analysis of the pavement structure layer with glass fiber high quality uniaxial plastic geogrid was carried out. The results show that laying glass fiber uniaxial plastic geogrid factory price in asphalt pavement structure can effectively reduce and delay early damage and improve pavement performance, and glass fiber uniaxial plastic geogrid manufacturers have good economic benefits.
Keywords: asphalt pavement; glass fiber wholesale uniaxial plastic geogrid; response analysis; road surface deflection
The addition of a high quality uniaxial plastic geogrid to the asphalt concrete pavement can enhance the strength of the pavement structure. A large number of construction practices have proved that the uniaxial plastic geogrid for sale can effectively prevent early damage such as cracking of the asphalt pavement and rutting, and improve the stress of the pavement structure, and comprehensively improve the performance of the asphalt concrete pavement.
As early as in the 1980s, the theory of adding plastic polymer grids to asphalt mixtures was proposed abroad, and it was promoted. In the early 1990s, China began to introduce plastic grids with relatively low cost. At that time, the cost of glass fiber wholesale uniaxial plastic geogrid was relatively high and did not receive attention. With the rapid development of China’s highway transportation industry, many universities and research institutes have successively studied glass fiber uniaxial plastic geogrid for sale and obtained a lot of research results, and their cost has also been greatly reduced and has been widely used in recent years. This paper mainly analyzes the construction technology and economic benefits of glass fiber high quality uniaxial plastic geogrid, which shows that it has good practical value.
1. Project Overview
The design of a highway adopts two-way four-lane road with hard shoulders on both sides and a separation belt in the middle. The roadbed has a full width of 27m. It adopts the asphalt pavement structure with a total width of 25.5m. It adopts three layers of asphalt concrete surface layer and the base layer is cement stabilized gravel. The semi-rigid base layer and the base layer are made of two-ash stabilized fly ash pellets. In order to improve the road performance of the asphalt pavement, a glass fiber wholesale uniaxial plastic geogrid is added to the pavement structure.
2. Basic functions of geogrid
2.1 Reinforcement function
Under a load of the vehicle, the surface structure of asphalt pavement is subjected to shear stress, the base layer is subjected to tensile stress, and the uniaxial plastic geogrid for sale can effectively disperse the stress, increase the overall modulus of the pavement structure, transmit tensile stress, and limit the lateral movement of the material. The frictional resistance between the structural layers can be increased to improve the overall stability of the pavement structure.
2.2 Reduce early damage of asphalt concrete pavement
(1) Reduce and delay the occurrence of cracks. The addition of a wholesale uniaxial plastic geogrid between the semi-rigid base layer and the asphalt surface layer can effectively improve the strength and road performance of the pavement material and improve the stress of the pavement structure. During the asphalt pavement construction process, micro-cracks are easily formed between the base layer and the surface layer because it is impossible to be completely filled with the asphalt cement. After adding the uniaxial plastic geogrid for sale, the expansion angle of the crack can be increased, which can effectively delay the generation and development of the crack.
(2) Improve the high-temperature resistance to rutting. The use of uniaxial plastic geogrid manufacturers can effectively improve the stability of the asphalt concrete skeleton structure. The high quality uniaxial plastic geogrid can withstand the load stress and transmit the stress to the surrounding asphalt concrete, spreading the local load stress and preventing the local overload from destabilizing and deforming.
2.3 Improve the fatigue life of asphalt pavement
Under the repeated action of long-term vehicle load, the asphalt concrete pavement structure is prone to fatigue damage, causing stress concentration on the local pavement structure, and then micro-cracks, cracks continue to expand, and the pavement structure is gradually destroyed. The addition of wholesale uniaxial plastic geogrid can effectively limit the displacement of particles inside the asphalt concrete, minimize the stress concentration, prevent the generation and development of cracks, and thus improve the fatigue life of the pavement structure.
2.4 Reduce the thickness of the asphalt layer
By adding a wholesale uniaxial plastic geogrid, the stress on the asphalt pavement can be effectively improved, the stress on each structural layer can be reduced, the early damage can be reduced, and the fatigue life can be effectively extended. Therefore, if the design is still designed according to the service life of the original road surface, the thickness of the road surface layer can be appropriately reduced, and this effect is more remarkable in the low stability asphalt concrete.
3. Pavement construction process
3.1 Technical indicators testing
The technical indexes such as tensile strength, elongation at break and mesh size of the glass fiber uniaxial plastic geogrid for sale were tested under the specified test temperature and humidity. The results are shown in Table 1, which meets the design and specification requirements.
Table 1 Test results of main technical indexes of glass fiber wholesale uniaxial plastic geogrid
3.2 Underlay construction
After the base layer is cleaned, the AH-90 heavy traffic petroleum hot asphalt is first sprinkled, and then the stone chips are sprinkled and rolled with a tire roller to form a lower seal layer.
3.3 Glass fiber geogrid anchoring method
The fiberglass uniaxial plastic geogrid manufacturers in this project are fixed by anchoring method. Before laying the fiberglass uniaxial plastic geogrid for sale, the uniaxial plastic geogrid factory price is laid flat and tightly, the horizontal overlap is controlled at 50-100mm, and the longitudinal overlap is controlled at 150-200mm. It is fixed by 50mm × 50 mm × 1mm iron and 50mm steel nails. The horizontal fixing distance should not exceed 20cm, and the longitudinal fixing distance should not exceed 50cm, as shown in Figure 1. Steel nails must not be nailed to the uniaxial plastic geogrid manufacturers to prevent damage to the grille.
Figure 1 Glass fiber uniaxial plastic geogrid for sale anchoring
3.4 Sprinkle through the (sticky) layer of oil
In order to ensure that the glass fiber high quality uniaxial plastic geogrid and the lower sealing layer are firmly bonded, a layer of transparent (adhesive) layer of asphalt can be sprinkled, and the amount of sprinkling is controlled by controlling the height of the sprinkling, the driving speed, and the height of the nozzle from the ground.
3.5 surface paving
The surface paving construction process is the same as that of ordinary asphalt pavement. During construction, attention should be paid to protecting the glass fiber high quality uniaxial plastic geogrid and repairing if damaged. Figure 2 shows the construction site of the asphalt surface layer.
Figure 2 asphalt surface construction site
4. Response analysis of adding fiberglass geogrid to the asphalt pavement structure
4.1 Road surface deflection
The road surface deflection can comprehensively reflect the total deformation of the asphalt pavement structure under the load of the vehicle. Take the horizontal distance range of 1~3m, and test the change of the road surface deflection after reinforcement. The result is shown in Figure 3. It can be seen from Fig. 3 that the curve of the road surface is W-shaped in the cross-section, and the slope of the curve of the deflection value becomes smaller as the distance between the center of the load increases, and the deflection value is the largest at the center of the load. The deflection value is the smallest.
See Table 2 for the deflection of the road surface at the center of the wheel gap and the center of the load before and after reinforcement.
Table 2 Test results of deflection value before and after reinforcement
Figure 3 Effect of reinforcement on road surface deflection
Comparing the test results of Table 2, it can be seen that the deflection value of the asphalt surface layer after the reinforcement is reduced, that is, the deformation resistance of the road surface structure is improved by adding the glass fiber high quality uniaxial plastic geogrid.
4.2 Vertical compressive stress
The vertical compressive stress applied to the pavement structure by the driving load is too large, which is easy to induce permanent deformation and affect the service life of the pavement. Figure 4 shows the variation of the vertical stress value of the bottom layer along the horizontal plane after reinforcement.
Figure 4 Effect of reinforcement on the vertical stress of the underlying layer
Table 3 shows the vertical compressive stress peaks of the structural layers before and after reinforcement of the glass fiber uniaxial plastic geogrid manufacturers on different layers. It is found from Table 3 that the reinforcement effect is best at the bottom of the middle layer, and the vertical compressive stress is greatly reduced. The bottom layer is the second, and the bottom layer is the smallest.
Table 3 Vertical compressive stress peaks under different reinforcement conditions
4.3 Shear stress
Automobile braking will produce shear stress on the asphalt surface layer, especially in the high-temperature season, which will easily cause shear deformation of the asphalt pavement. The practice has proved that the shear stress at 8 cm below the asphalt surface layer reaches the maximum, but as the depth further increases uniaxial plastic geogrid factory price, the shear stress decreases continuously. Figure 5 shows the shear stress curves for different reinforcements.
It can be seen from Fig. 5 that the shear stress curve obtained by reinforced at the bottom of the middle layer and the bottom layer is basically the same as that when the rib is not reinforced, so the reinforcement of the two positions has less influence on the shear stress; Although it has little effect on the negative normal stress uniaxial plastic geogrid factory price, it can significantly reduce the positive maximum shear stress.
By analyzing the changes of road surface deflection, vertical tensile stress and shear stress of the pavement structure layer before and after reinforcement, it can be known that a glass fiber high quality uniaxial plastic geogrid is provided at the appropriate layer of the asphalt pavement, which can strengthen the pavement structure. Effectively improve road stiffness.
Figure 5 Shear stress curve under different reinforcement conditions
5. Analysis of economic benefits
5.1 Project Cost Analysis
In terms of raw materials, only the glass fiber uniaxial plastic geogrid manufacturers are added to increase the material cost by about 15 yuan·m-2. The other materials are the same as the ordinary asphalt pavement, and the increase is less. The labor cost of the artificial station has increased, but due to the simple construction process and high speed of the grid, the increased labor costs for the manual machinery are not much.
5.2 Analysis of economic benefits
(1) Adding a uniaxial plastic geogrid factory price can reduce the thickness of the surface layer by 2 to 5 cm, and at the same time, it can extend the service life, and the cost per mile of pavement construction is about 612,000 yuan.
(2) Glass fiber uniaxial plastic geogrid manufacturers can comprehensively improve the performance of asphalt pavement, improve the running condition of the pavement, reduce the accident rate, and improve the driving speed and transportation efficiency. According to the design life of 15 years, the cost per kilometer is not less than 200,000 yuan.
(3) Glass fiber uniaxial plastic geogrid factory price can improve the service life of asphalt pavement and reduce the number of overhauls. It is estimated that the cost of an overhaul can be no less than 200,000 yuan per kilometer.
In this paper, through the test verification and data analysis, combined with the stress analysis of each structural layer, the following conclusions are drawn.
(1) Glass fiber uniaxial plastic geogrid factory price can greatly improve the performance of asphalt pavement structure, prevent early diseases and extend the service life of the pavement.
(2) The glass fiber uniaxial plastic geogrid factory price is placed on the bottom of the asphalt pavement, which can effectively reduce the deflection of the road surface and the shear stress of the surface layer, and improve the structural rigidity of the pavement.
(3) Reinforcement on the upper, middle and lower layers of the asphalt pavement can reduce the vertical stress of the corresponding layer of the asphalt pavement, and the reinforcement effect at the bottom of the middle layer is the best.
(4) Through the analysis of engineering examples, the addition of glass fiber uniaxial plastic geogrid manufacturers can bring obvious economic benefits to asphalt pavement construction.