Construction method for joining new and old pavements in road widening project

Abstract

The invention discloses a method for joining new and old pavements in a road widening project. The method comprises the following steps: 1. milling the edge of a bituminous pavement layer of an old road to form lapped steps, and manually clearing away loose aggregates on a side surface; 2. retaining the original cement concrete slabs for sections of the old road with high-quality cement concrete slabs on the bituminous pavement; 3. arranging a drainage system below lap seams, wherein the drainage system is positioned on the top surface of a roadbed of the new-built widened road; 4. casting stepped structures with internal tilt angles in situ by three layers from top to bottom at the base layer and sub-base layer of the pavement of the new-built road and at the lap joint between the new and old pavements; 5. before the top-layer structures of the stepped structures are cast, drilling holes on the side surface of the old road for planting transverse steel bars, arranging longitudinal steel bars at the top layers of the structures, and welding the longitudinal steel bars with the transverse steel bars to form a meshed whole; 6. longitudinally carving grooves at the joining seam on the top surface of the spliced new and old roads, pouring hot asphalt into the grooves, and longitudinally paving an anti-crack paster at the joining seam; and 7. texturing the top surfaces of the stepped structures.

Description

technical field [0001] The invention relates to a method for connecting roads, in particular to a method for connecting new and old roads in road widening. Background technique [0002] In highway road widening and expansion projects, due to the difference in structure and strength between the new and old roads, as well as the uneven settlement of the new and old roads and the continuous effect of vehicle loads, road diseases often occur at the junction of the new and old road surfaces. In addition, most of the original old roads did not have a drainage design between the layers of the pavement structure. In addition, the characteristics of dry shrinkage and temperature shrinkage of the new and old materials at the junction of the pavement base layer are different, which will inevitably lead to the generation of longitudinal cracks. [0003] For the connection between the old pavement (cement concrete composite asphalt pavement) and the new widened pavement (semi-rigid base ...

AI Technical Summary

Problems solved by technology

[0006] 1. To connect the new and old pavement structure layers, it is generally necessary to step the pavement structure of the old road, but for the composite pavement, it is difficult to mill the cement concrete slab, and the steps cannot be effectively formed, so The connection between the new and old roads can only be vertically connected, which leads to great hidden dangers in quality; although some schemes simply add a step structure at the connection, the connection between the new and old roads has not effectively formed a whole, and has not solved the problem of synergistic force on the new and old roads;

[0007] 2. Due to the difference in the characteristics of the new and old pavement joint materials, longitudinal joints are often formed at the joints. Once the water and rainwater between the old road layers penetrate into the structural layer along the lap joints and cannot be discharged smoothly, it is easy to cause the bottom of the base layer to be hollowed out. Road diseases such as road subsidence;

[0008] 3. The joints of new and old pavement do not have the ability to prevent reflection cracks;

[0009] 4. There are long sections of transverse cracking of cast-in-place plain cement concrete

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