Discover some interesting facts about how the Perimeter Access Road at the Canadian Port of Entry is built.
Click or hover over the coloured numbers or the construction machines to learn more.
The first stage in the construction is known as earthworks. Trees, shrubs, stumps and other organic material is removed by bulldozers. Some of the waste material is reused for landscaping.
Utility lines for electricity, telephone and cable television cannot cross over the Port of Entry and those near the new road need to be buried underground. A trench is dug alongside the roadway. The cables are fed in plastic pipes which are then covered in concrete. Gas lines and water pipes are buried in separate trenches.
Dump trucks deliver gravel and crushed stone known as aggregate to the site. Bulldozers and graders move the aggregate on the roadbed to create a level surface. The aggregate is added in layers and compacted by rollers to create a solid foundation on which the concrete roadbed can be laid.
The next phase is the excavation of trenches for drains and storm sewers. These are needed to allow rain to drain away from the road surface and make it easier for vehicles to travel during storms.
Precise amounts of sand, aggregate, cement and concrete are mixed at an automated portable concrete plant temporarily installed on site. The plant manufactures more than 10,000 cubic metres of concrete that is needed in building the new roadway.
Another layer known as the Open Graded Drainage Layer (OGDL) is placed on top of the compacted base. This 10-centimetre layer is a mixture of stone and cement which is spread by a paving machine. The OGDL along with the underlying compacted aggregate, forms the foundation for the concrete pavement which is the next step in the process.
Once the foundation is finished, the road surface is ready for paving. Concrete mixed at the plant is loaded onto trucks which place the concrete immediately in front of a specialized piece of equipment known as a slipform paver. The machine gathers the concrete and spreads it to form the road.
Workers insert joints called "baskets" every four metres along the road bed. These joints allow the concrete slabs to expand and contract with changes in temperature without breaking.
As the slipform paver moves across the roadbed, it vibrates the concrete so that it settles evenly and then trims it to the correct height.
Once the road bed has been poured, curbs and gutters are installed. Concrete is forced through a mold on a "curbing machine" which casts the curb and gutter in one piece.
