What are the methods to repair poor concrete pavement flatness?

🎈 Mild unevenness

– Grinding treatment

– Applicable situations: Applicable to situations where there are small bulges or unevenness in the concrete pavement, the height of the bulge is generally within a few millimeters, and the unevenness is relatively mild.
– Operation method: Use a pavement grinder to grind the uneven parts, and grind off the raised parts to make the pavement flat. When grinding, pay attention to controlling the depth and range of grinding to avoid excessive grinding causing the pavement to become thinner or new unevenness. After grinding, clean up the debris and dust on the pavement in time.

– Filling and leveling

– Applicable situations: Applicable to situations where there are shallow potholes or local depressions on the pavement, the depth is usually less than 2-3 cm, and the area is not large.
– Operation method: First clean the potholes and remove debris, dust and loose concrete fragments. Then use cement mortar or special pavement repair materials with the same or higher strength grade as the pavement concrete to fill them. When filling, the material should be fully compacted and smoothed to ensure that the surface after filling is consistent with the surrounding road surface. In order to ensure the adhesion between the repair material and the original road surface, a layer of interface agent can be applied to the surface of the pothole before filling.

🎈 Moderate unevenness

– Thin layer repair

– Applicable conditions: When the road surface unevenness is more obvious, the depth of the potholes or depressions is about 3-5 cm, and the area is large, the thin layer repair method can be used.
– Operation method: First, cut the area to be repaired into a regular shape. The depth is determined according to the degree of unevenness, generally about 3-5 cm. Then clean up the loose concrete in the cut area and treat the base appropriately, such as compaction, cleaning, etc. Then lay a thin layer of repair material that matches the performance of the original road concrete, such as polymer-modified concrete or high-performance repair mortar. When laying, use tools such as flat vibrators or trowels to vibrate and compact the materials, smooth them, and ensure that the repair layer is tightly combined with the original road surface and the surface flatness meets the requirements.

– Milling and re-paving

– Applicable situations: Applicable to large areas with poor road flatness, serious unevenness, multiple potholes of varying depths, wavy unevenness, etc.
– Operation method: Use a road milling machine to mill off the uneven surface of the road. The milling depth is generally about 5-10 cm, and the specific depth is determined according to the actual situation of the road surface. After milling, clean up the debris and dust, inspect and treat the base layer, and repair and compact any damaged or loose parts. Then re-pave the concrete road surface according to the design requirements, including paving, vibration, troweling and other processes to ensure that the flatness of the newly laid concrete road surface meets the standard. After the concrete is poured, it should be maintained in time to prevent quality problems such as cracks.

🎈 Severe unevenness

– Partial plate replacement

– Applicable situations: When the concrete pavement is severely broken, sunken or uneven over a large area, and the base is also severely damaged, partial plate replacement is required.
– Operation method: First determine the range of the plates that need to be replaced, use a cutting machine to cut the plates neatly around, then remove the broken concrete plates, and clean up the debris and loose materials on the base. Reinforce the base, such as using compaction, replacement and other methods to ensure that the bearing capacity and stability of the base meet the requirements. Then re-pour the concrete plates according to the design requirements, including installing the formwork, tying steel bars (if required), pouring concrete, vibrating and compacting, and smoothing. After pouring, strict maintenance must be carried out, and traffic will be opened after the concrete reaches the design strength.

– Overall renovation

– Applicable situations: If the overall flatness of the concrete pavement is extremely poor, and there are large-scale defects such as severe cracks, potholes, and subsidence, and after evaluation, it is believed that the repair can no longer meet the use requirements, or the repair cost is too high, overall renovation can be considered.
– Operation method: First, the original pavement should be demolished, the concrete pavement should be crushed and transported away, and the base layer should be thoroughly inspected and treated. If there are weak soil layers or poor geological conditions, corresponding treatments should be carried out, such as replacement and reinforcement. Then, according to the design plan, the pavement structure should be re-laid, including the base layer, subbase layer, surface layer, etc., and the construction should be carried out in accordance with the construction specifications, and the thickness, compaction and flatness of each layer should be strictly controlled. During the construction process, quality inspection and control should be strengthened to ensure that the performance indicators of the new pavement meet the design requirements. The pavement after overall renovation needs to be maintained and debugged for a period of time. After all indicators are stable, it can be officially opened to traffic.