Guide Reading: "Fiberglass grids can effectively alleviate reflection cracks. Because the modulus of glass fiber grids is very large. It in asphalt interlayer can effectively restrain stress and release strain. Thus, the reflection cracks can be slowed down. Let's learn about the principle of fiberglass grids. "
Reflective cracks are caused by the stress concentration in the asphalt overlay above the old concrete surface. And the stress concentration is caused by the large displacement near the joint or crack. Reflective cracks includes horizontal displacement due to temperature and humidity changes and vertical shear displacement due to traffic loads. The former results in concentrated tensile stress in the asphalt overlay above the joint or crack. The latter makes the asphalt overlay above the joint withstand greater flexural and tensile stress and shear stress.
Because the modulus of geogrid is very large, reaching 67 Gpa, it is used in asphalt overlay as hard interlayer with high stiffness. Its function is to restrain stress and release strain. At the same time, as the reinforcement material of asphalt concrete, it can improve the tensile and shear resistance of overlay structure, so as to reduce cracks. Practice shows that the corresponding crack energy of a horizontal crack with changed direction can move 0.6 meters from its starting point, and the reinforced material with a width of more than 1.5 meters can help to ensure that the energy dissipates completely on both sides of the crack.