Each new road begins with soil and rock construction
Nature does not always provide the ideal ground conditions – whether for civil engineering or structural engineering projects. Quite often, the existing soil requires preliminary treatment to improve its bearing capacity. In other places, massive rock formations need to be levelled. Which methods are used to lay the foundations?
Since the soil is frequently loose and insufficiently cohesive, earthworks are required before the base course, binder course and surface course can be laid. Compaction is the most important process in earthworks. The purpose of compaction is to reduce the volume of soil filled with air and water. This gives the soil the desired properties: it becomes more resistant to the stresses imposed by traffic and climate.
Road construction requires a stable base. How to improve the nature of existing soil? What are the binding agents used for this purpose?
Extremely cohesive and wet soils are not suitable for compaction by rollers. In such cases, the existing soil needs to be stabilized first to improve its bearing capacity and prepare it as a suitable base for the upper pavement structure.
Before commencing the actual road building operation, the prerequisites for doing so need to be established. When driving roads through rocky terrain, cold milling machines or surface miners are used to prepare the ground for road construction – or to cut the route, as the professionals would say.
The base layer of a road lays the foundation for the upper pavement structure. It must offer excellent bearing capacity, be capable of withstanding a broad range of different climatic conditions, and remain functional over several decades. What materials are used for the construction of base layers? What properties do they need to possess?
The frost protection layer prevents water from rising into the road body – thus preventing frost damage to the superstructure. To this end, rock is crushed and sieved into graded aggregates, which are then laid and compacted.