The glass fiber geogrid is the aggregate of the network structure asphalt mixture, which can penetrate into it to form a composite mechanical interlocking system. This restriction hinders the movement of the aggregate. The asphalt mixture can get better compaction and greater bearing capacity, and can improve the load transfer capacity and reduce the deformation. It has higher structural strength. Therefore, the glass fiber geogrid plays a skeleton role in the road cover.
Subgrade is one of the most important structural organizations in the highway system. Under the action of the variable stress of the means of transport, the local area of the foundation layer bears large stress and strain. Due to the long-term local stress change, the foundation layer begins to appear settlement, displacement, cracking and other phenomena. Because of the change of the foundation layer, the irregular curvature of the road surface changes, causing cracks, wrinkling and other phenomena. Therefore, it is very important to enhance the basic layer.
The use of specially treated GFRP geogrid can greatly improve the overall strength of the foundation layer, and its effect is just like that of reinforced cement concrete. The reinforcement mechanism of the interaction between the soil and the glass fiber geogrid. A lot of experiments in the laboratory show that the reasonable arrangement of the glass fiber geogrid in the soil can significantly reduce the vertical stress and the horizontal stress of the soil, significantly improve the shear stress (the friction between the soil particles), give full play to the shear strength of the soil, and greatly improve the bearing capacity of the soil , deformation resistance and crack resistance. The cohesive force effect, isolation effect, corrugation effect, arch effect, inlay effect and other reinforcement effects of GFRP geogrid in reinforced soil, some of them appear successively, some of them are overlapped cross effects. These overlapped composite effects will eventually change or stop the formation and development of plastic zone.
The strength and rigidity of GFRP geogrid are high. Adding into the asphalt concrete structure can improve the strength and performance of the pavement materials, and change the stress distribution of the pavement structure
① Setting Geogrid on the surface of old cement concrete slab can change the stress state of asphalt layer under the action of vehicle load and temperature, greatly reduce the stress concentration of asphalt layer at the joint, thus hindering the generation and development of reflection cracks.
② Setting geogrid can increase the overall stiffness of the pavement, reduce the deflection of the asphalt surface, and improve the high-temperature rutting resistance of the asphalt overlay.
③ High strength geogrid does not rely on its own large deformation to diffuse stress, its crack prevention function is essentially an isolation function。 It separates the stress concentration area at the tip of the joint (crack), while the geogrid with high strength bears large tensile stress, thus hindering the rapid expansion of the crack。
matters needing attention
① Strictly control the access of vehicles transporting the mixture. It is forbidden to turn sharply to brake or pour the mixture feet on the grid layer to prevent damage to the fiberglass geogrid.
② Glass fiber geogrid back glue is easy to dissolve in rainy days or when the road surface is wet, construction is not allowed.
③ When the grid is laid, the road surface temperature should not be too high.
④ When laying the geogrid in full width, it is necessary to pay attention to the damage of vehicles to the geogrid during the construction of asphalt surface course. It is recommended that after the geogrid is laid, appropriate amount of guami stone be sprinkled to prevent the geogrid from sticking and curling.
I believe that after reading the above content, we have a certain understanding of how to improve the cement concrete pavement with geogrid. I hope it will help you.