Road construction is a tedious process; depending on the length of the roadway, it may take several years to finish. It requires careful planning, numerous assessments, and a range of assessments, including environmental and structural investigations and several construction engineers and plant machinery.
Our highways are evidence of the innovation of human engineers. Our roads’ continued security and reliability depend on every construction element, from the solid foundations provided by aggregates to the flexible, long-lasting surfaces provided by asphalt and concrete.
But here, we will discuss some materials used to construct roads.
Asphalt
Asphalt is at the top of the list. This material is petroleum in a viscous liquid state. It takes the shape of asphalt concrete, a composite material when it comes to pavements and the construction of roads.
About 70% of asphalt and 30% of aggregate particles comprise asphalt concrete. For various reasons, asphalt is one of the materials most frequently used in road construction. The most important reason is that this commercial asphalt is entirely recyclable.
Sealcoating for Prevention of Asphalt
Sealcoating adds a second layer to the top of your asphalt driveway. This layer prevents the asphalt from environmental factors, oxidation, and the inevitable occasional fuel spills.
Sealcoating may preserve the beauty of your road surface over time and provide great protection against wear and stress on your driveway.
Cement Concrete for Road Toughness
Regarding toughness and endurance, cement concrete is the greatest material for roads. It is also very flexible and simple to build with. The substances that go into making it are cement, water, fine and coarse aggregates, and chemical additives, which make up 25–40% of the concrete’s weight overall. The fact that cement-based concrete increases carbon emissions is one of its main disadvantages.
Well-mixed concrete sets and hardens quickly due to the great binding property of cement. It also has relatively few gaps. Water-curing the concrete creates a long-lasting, sturdy road surface resistant to repeated hits from large commercial trucks.
Stone Aggregate
Undoubtedly, the most crucial element of the materials used to build roads is stone aggregate, often referred to as mineral aggregate. The process involves fragmenting naturally occurring rocks to create fine aggregate, similar to sand, or coarse aggregate, like gravel.
Cement concrete, bituminous mixtures, granular bases, and sub-bases all employ aggregates. Additionally, they are the main part of water-bound macadam roads, which are comparatively less expensive.
Recycled Materials
Recycled materials can also be used for construction projects that are more environmentally conscientious. The materials discussed in this section are secondary and tertiary waste materials and by-products, but asphalt is typically recycled. These materials include, but are not limited to, recycled crushed glass, foundry sand, plastic wastes, scrap tires, mine wastes, and various coal combustion products.
Even though these materials are frequently used in road building, issues and knowledge gaps still need thorough investigation and evaluation to create better roads while protecting the environment. A few of these problems are structural integrity and long-term performance in large volume and weather-exposed environments.
