The characteristics of municipal roads include a high concentration of underground pipelines, particularly precast concrete inspection wells for stormwater and wastewater on the lanes. They are not only an indispensable part of urban infrastructure but also an inevitable aspect of urban road construction, as well as a challenging component for asphalt concrete road surfaces.
For cement concrete road surfaces, precast concrete manholes are typically reserved in hexagonal or circular positions within the concrete road. Once the cement concrete road reaches a certain level of strength, precast concrete manholes are installed in the reserved locations. Guangzhou Precast Concrete Manhole Manufacturer introduces how to install the manholes.
Pre-cast Concrete Manhole
Asphalt concrete pavements require different installation methods depending on varying construction conditions. Common primary installation methods include:
1. Asphalt mix is laid on cement concrete road surfaces, and precast concrete manholes are installed. Typically, the original road surface is removed first, and the manhole shafts are raised. After the asphalt concrete road is shaped, the road around the manholes is cut into hexagons, and the remaining materials are chiseled away. After installing the manholes, asphalt mix is laid within the hexagons.
Pre-cast Concrete Manholes
2. Asphalt mixture is laid on old asphalt roads, and manholes are installed. Generally, the original road surface is excavated to raise the manhole well or to leave space at the original manhole location. After the asphalt concrete road is shaped, the road around the manhole is cut into hexagons, the remaining material is chiseled away, or the manhole is installed within the reserved hexagonal or circular space, followed by laying asphalt mixture within the hexagonal or circular area.
3. Asphalt mixture is laid on the newly constructed subgrade, and inspection wells are installed. Generally, temporary installation methods for inspection wells are employed. After the asphalt concrete pavement of the entire road width is completed, the inspection wells are cut into hexagons around them, or the remaining materials are cleared from the pre-reserved circular locations before installing the inspection wells.
After installing the manhole using the aforementioned method, due to the weak foundation treatment around the manhole, the asphalt road surrounding the manhole is a secondary paving, which typically has poor rolling effects. Over time, this can lead to沉降 of the asphalt road around the manhole, creating an indentation resembling a "belly button," affecting the road's stability and aesthetics, particularly the ride comfort. When using mechanical leveling, the temporary installation of the manhole can impact the leveling and rolling operations.
