Crack-proof paste (also known as crack-proof paste and YN-crack-proof paste) is composed of asphalt-based polymer, high strength tensile matrix, high temperature resistant and asphalt-compatible high strength fabric. It can reduce and block the temperature shrinkage stress of the asphalt concrete pavement which produces cracks or spalling, so it also reduces the tendency of cracks reflecting through the surface layer. Paving and pavement can isolate the base layer from the upper abrasive layer, so that the upper layer is free from the influence of multi-direction displacement and shear stress, and can be used in highways, bridges, airports and so on.
Main performance:
1. Isolation. Laying anti-cracking paste separates the cracked surface from the asphalt surface, avoids the direct contact between the cracked surface and the asphalt surface. The tensile stress of the base crack can not be transmitted directly to the asphalt concrete surface. Although it reduces the bonding force between the base and the surface layer, the high polymer anti-cracking paste can make the upper and lower layers adhere well to form a whole and bear the effect of vehicle load together, which is enough to prevent the interface. Relative displacement of upper and lower layers keeps continuous.
2. Reinforcement. The crack-resistant patch has certain strength and can withstand certain crack tension stress. When the crack tension stress increases and is greater than the tensile strength of the crack-resistant patch, the crack-resistant patch begins to deform, and then the surface layer begins to withstand the tensile stress transmitted by the crack-resistant patch. The crack-resistant layer will bear all the tensile stress of cracks, and obviously the crack-resistant layer plays a reinforcing role. In this sense, it improves the tensile strength of pavement structure layer.
3. Energy dissipation and buffering. Crack-resistant paste is a kind of material with certain extensibility. Polymer has good low-temperature flexibility. It is laid between asphalt pavement layers, which is equivalent to setting an elastic layer. The tensile stress of base crack extends to a wider range through crack-resistant paste polymer, thus alleviating the stress intensity at the crack, and the elastic layer can absorb part of the tensile energy.
4. Water-proof and seepage-proof function. Crack-resistant polymer can form a complete waterproof and impermeable layer, which can cut off the water from the road surface to permeate the roadbed, thus protecting the strength of the base, so that the properties of the base material will not deteriorate further. Anti-cracking paste used in asphalt pavement can effectively inhibit the upward propagation of cracks, and play an anti-cracking and energy absorption role in practical projects.
Crack-resistant pasting construction technology:
1. According to the width of pavement cracks (joints), the specifications of anti-crack patches are selected, and the anti-crack patches below 1_-3_are selected to be at least 24 cm.
The cracks (joints) with a width of less than 2 and 3_-5 are selected as anti-cracking patches with a thickness of at least 32 cm.
3. The cracks (joints) with a width of 5-19 mm must be cleaned up and filled with sealant, followed by 48 cm anti-cracking seams.
4. Cracks (joints) and subsidence areas with a width of more than 19 mm must be cleaned up, filled with mortar, sealant or asphalt mixture and compacted to the existing height, and then applied with 98 cm anti-cracking seam.
5. Cracks or pits with a width of more than 50 mm must be cleaned up first, then filled with mortar or hot asphalt mixture and compacted to the existing height, and then filled with 98 cm anti-cracking seam.
6. Leveling treatment must be carried out for cracks (joints) and subsidence areas with different heights.
Matters needing attention:
(1) Cement concrete pavement must be dry before construction. No construction is allowed in wet or rainy or snowy conditions.
(2) After construction, it is necessary to use sand bag or rubber tyre roller to compact the "anti-crack sticker" in order to prevent rainwater from entering the "anti-crack sticker" bonding surface before spreading asphalt concrete. If it is expected to rain heavily before spreading asphalt concrete, sealant should be used to seal both sides of the "crack-proof paste".
(3) It is not suitable to construct when the temperature is below 5 C.
(5) When asphalt concrete is paved, the vehicle shall not roll around on the "crack-proof sticker" in place.
(5) When the slope is more than 5%, the width of "anti-cracking paste" should not be greater than 330 mm. When paving asphalt concrete at the bottom, slippage may occur. It should be repaired in time, which will not affect the quality of the project.
(5) The total thickness of paving asphalt concrete should not be less than 6 cm.
When the height difference between adjacent sides is greater than 1 cm or there are many holes, it is necessary to levelize the area and then lay it in order to prevent the damage of the "crack-proof sticker" which is laid on the depression from being subjected to gravity. Leveling materials can be leveled with epoxy mortar or asphalt mixture.
