When it comes to civil construction, have you ever stopped to wonder how roads are built? No, not roads for plastic toy cars but roads for cars in real life! If you are interested to know more, then look no further. Here is a quick look at the various processes that are involved in building public roads.
Just like anything, the very first step in building a public road requires extensive planning. The people involved in this process includes both construction experts and engineers, and they come together to figure out what type of road should be made as well as what material it should be made from. The factors that influence their decisions are the type and amount of traffic the road will likely see.
The planning phase can span across a few months, and this even applies to simple roads. If complex roads have to be built and they involve different structural elements, such as overpasses or bridges, the project team will need years to plan. Other factors that have to be considered by the planners include safety, availability of materials, cost and overall environmental impact of the road.
Follow-ups via regular meetings
By the end of the planning phase, solid plans for the road to be built should have been developed by experienced construction experts and surveyors. Government officials and lawyers will step in to purchase pieces of property if the land is privately owned.
Next, public meetings will be held to address citizens’ concerns and federal, state or local governmental entities that are in charge of building the road will solicit construction bids from a range of competent contractors that can build the road economically. The construction begins only after a contractor is selected. This phase can last for a few weeks to several years.
Beginning the construction phase with mandatory earthwork
Earthwork is the first part of the construction phase and it involves the use of huge earth-moving machines. A solid foundation is needed to ensure that the road lives up to its expected lifespan. Dirt that is delivered by dump trucks will be moved around by graders and bulldozers to create a level surface.
The level surface will provide adequate support for the road for many years to come. Next, gravel is added in layers and will be further flattened and compacted by the relevant machines. If necessary, storm sewers and drains will be installed as early as possible to effectively drain away rainwater from the road surface.
Paving the roads with concrete or asphalt
Once the foundation has set and has been inspected by the relevant authorities, the way will be paved. In most cases, concrete and asphalt are the preferred materials. Factors that determine which material to be used include the amount of traffic, costs and more. If concrete is chosen, it is often a mixture of crushed rock, cement and sand. Liquid concrete will be poured in to forms (which are special types of steel moulds). With the aid of a special finishing machine, the concrete will be vibrated until it settles evenly and then trimmed to the correct height.
If asphalt is the chosen road material, it will use bitumen (an oil-based substance) to make crushed rock and sand stick together like glue. In addition, it will be heated to approximately 300° F before being transported to the construction site. Asphalt will then be compacted onto the foundation that’s already in place.