How to build roads?
Only at first glance, the laying of new highways seems to be not a difficult task. However, few people know how to build roads, and how much work needs to be done, paving the next highway. Most of us believe that the main job is asphalt paving. However, this is not quite true.
Work on the construction of a new road with its design begins. Engineers should predict the composition of the traffic flow (buses, trucks and cars) and traffic intensity. Based on these forecasts, the width of the road, the required number of lanes, the thickness of the asphalt concrete pavement and the base will be laid.
Be sure to take into account information that is extracted by surveyors. Freeways will be laid wherever a minimum amount of earthwork is required. Be sure to take into account the composition of the soil. For example, if clay and loamy soils predominate at the site of the projected road, this suggests that such a soil will be particularly mobile in the spring, when it is saturated with moisture.
When the project is approved, the preparatory stage begins. An organization is appointed that will be engaged in the construction of this road (general contractor).
The excavation phase begins. Interestingly, a flat plain is the most costly option for laying a new highway. All the soil for the foundation device will need to be delivered, and this will necessarily affect the rise in price of construction.
How to build roads on rough terrain? Such a relief is considered to be the most optimal, since the extra soil from the elevations moves to the lowlands. The cost of moving it under the base will be minimal, and the profile of the road will have a smaller height difference.
After the construction of the roadbed, comes the turn of sand bedding. This layer will ensure the stillness and stability of the future road. Sand is used because it has excellent characteristics with high humidity. Compared to other soils, it is least susceptible to landslides and shifts when wet. The sand is well rammed and rolled with rollers.
After the sandy cushion, a sand-gravel mixture is placed, and a layer of rubble is placed on it. These two layers reinforce the base. The stones in these mixtures give them the necessary hardness. These layers also need to be tightly rammed.
How to build roads, putting on them asphalt mixture? Asphalt pavement can have one or two layers. Large particles are typical for the lower layer, and its thickness can be 10 cm or more. The second (upper) layer of asphalt has a minimum thickness of 5 cm. It provides protection for the main (lower) layer and provides low noise when driving.
A large number of specialized equipment is used in road construction: bulldozers, drilling machines, excavators, asphalt pavers, lifting machines, road rollers, tractors, mobile mobile laboratories.
When performing preparatory work, including clearing the area from trees and stones, apply lifting machines and graders. Often the equipment is equipped with a whole set of interchangeable attachments that correspond to the type of work performed.
For soil compaction,sand and stone pads are used rollers of static action and vibratory rollers, and the laying of asphalt concrete pavement is carried out by pavers.