Concrete roads have been in use for several decades, and their popularity has been growing steadily. These roads are known for their durability, comfort, and performance. As technology has improved, concrete roads have become an even better choice for building roads and other infrastructure.
In this article, we will discuss the many kinds of concrete roads and the advantages they bring. We look at the different ways concrete roads are built, from plain concrete pavements with joints to continuously reinforced concrete pavements.
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Concrete road: What is it?
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Concrete roads are a type of highway surface made by blending Portland cement, sand, coarse aggregate, and water to form a mixture that is poured and compacted to form a durable, long-lasting surface. Unlike flexible pavement surfaces, concrete roads are not easily damaged by things like cracks, ruts, and potholes. As a result, they are more durable and last longer. resulting in fewer traffic disruptions and reducing the need for constant repair and upkeep.
One of the best things about concrete roads is that they don’t need much upkeep. This means that there are fewer traffic jams and less need for constant repairs and maintenance. With the right planning, concrete roads can be a long-lasting, low-maintenance solution for highways that are often crowded.
Concrete road: Structural components
The structural parts of a concrete road are a big part of how strong, stable, and long-lasting it is as a whole. The different layers of the concrete road work together to spread the weight of the cars and prevent wear and tear. They are:
01. Surface course
The surface course is the top layer of a concrete road that provides a smooth and durable surface for vehicles to travel on. It is important for this layer to be resistant to wear and able to hold up under the weight of the vehicles. Depending on the type of construction, the surface course can be made of granular, bituminous, or cement concrete material. In flexible pavements, the bituminous surface serves as the wearing course, while in rigid pavements, the concrete surface acts as both the base course and wearing course.
02. Base course
The base course is an important part of a concrete road that goes underneath the surface course. Its main job is to make sure that all the layers of the road get the same amount of weight from the cars. The base course is made of granular or bituminous material and plays a structural role in the pavement. It gives the road the foundation stiffness and structural strength it needs and is the most important layer in transferring the stresses caused by traffic impacts through the wearing course.
03. Sub-base course
The sub-base course is an important component of a concrete road that lies just below the base course. It gives the other layers of the road more support and helps spread the weight of the cars out more evenly. The sub-base course helps prevent soil grains of the subgrade from infiltrating the base course and also helps counteract frost action. It is made of stabilised soil or a mix of different types of soil that makes it easier for water to drain away from the pavement. This layer is needed when the subgrade isn’t very good and needs to meet certain requirements for gradation, strength, and plasticity.
04. Subgrade
The subgrade is the base of a concrete road. It is made of natural soil that has been packed down and is right under the pavement layers. It serves as a uniform support for the pavement and bears the entire load of the pavement along with the weight of the vehicles. The formation level, which is the top surface of the subgrade, is based on how the land is laid out and what it is made of. It can be built over a bank, in a cut, or at the natural ground level. The subgrade is crucial for ensuring the stability and longevity of the concrete road.
Concrete road: Types
Here are the different kinds of concrete road pavements that are used to build roads that last a long time and are resistant to wear and tear, cracking, and other problems. Each type is made to meet a different set of needs and has its own advantages to meet the needs of modern traffic and infrastructure.
01. Jointed Plain Concrete Pavement (JPCP)
Jointed Plain Concrete Pavement relies on contraction joints to minimise cracking. The distance between the transverse joints is carefully chosen so that changes in temperature and humidity don’t cause cracks to form between the joints. JPCP does not use any reinforcing steel, making it a simpler and more cost-effective option for some road construction.
02. Jointed Reinforced Concrete Pavement (JRCP)
Jointed Reinforced Concrete Pavement is similar to JPCP, but it includes steel mesh reinforcement, which is sometimes referred to as distributed steel. This kind of concrete pavement makes the joints further apart on purpose and uses reinforcing steel to keep cracks in the middle of the panels from getting bigger. The reinforcing steel makes the pavement stronger and more stable, which makes it a good choice for roads with a lot of traffic.
03. Continuously Reinforced Concrete Pavement (CRCP)
Continuously Reinforced Concrete Pavement is a type of concrete pavement that uses continuous, longitudinal steel reinforcement without any transverse joints, except for end-of-day header joints, bridge approaches, and transitions to other pavement structures. The transverse cracking that happens in all new concrete pavements is dealt with in this type of pavement by reinforcing it all the time.
The base layer of the pavement and the longitudinal reinforcement keep the volume of the pavement from changing due to cement hydration, thermal effects, and drying from the outside. This keeps tensile stresses from building up in the concrete. This results in a more durable and long-lasting pavement solution for heavily trafficked roads.
Concrete road: Steps involved in construction
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Building concrete roads is a complicated, multi-step process that needs to be carefully planned and carried out. The following are the 13 key steps involved in the construction of concrete roads:
01. Preparation of subgrade
The first step in building a concrete road is getting the subgrade ready. To do this, the ground needs to be shaped and levelled to make a stable base for the concrete road. Before proceeding, the subgrade must be cleaned and made to the right grade and profile.
02. Placing the forms
The next step is to place the forms. These are used to mould the shape of the road and are fixed to the ground using stakes. For the concrete not to stick to the forms, they need to be properly braced and oiled.
03. Watering the prepared subgrade
As soon as the forms are in place, water should be applied to the area that will receive the concrete. Sprinkle some water on it and let it soak up as much as it can.
04. Batching of materials
The concrete mix must be made in the correct proportions of ingredients, including fine and coarse aggregates. This step is called batching and involves measuring out the correct amounts of each ingredient.
05. Transporting and laying the concrete mix
The mixed concrete is then transported to the site. It is deposited rapidly on the subgrade in a layer of a specified thickness.
06. Compaction
The concrete must be packed down to make sure it is dense and free of air pockets. To do this, you can use a heavy screed or tamper with the right kind of handles, a finishing machine powered by electricity, a vibrating hand screed, or a slab screed vibrator.
07. Floating
The next step is to float the surface of the concrete to provide an even surface without corrugations. This is done with a large, flat tool that is pushed across the surface of the concrete.
08. Belting
Belting is done just before the concrete starts to harden. It involves using a tool to press down on the surface of the concrete to make it harder and smoother.
09. Brooming
Brooming is the process of drawing brushes at right angles to the centerline of the road from edge to edge. This contributes to the formation of a rough surface that provides grip and prevents vehicles from sliding.
10. Edging
Before the concrete can be entirely cured, it must be completed around the outside using an edging tool. Having a straight edge that won’t sag throughout the course of the road’s lifetime is much easier to achieve using this method.
11. Joint filling
The cracks in the concrete road need to be filled with the right kind of sealing compound so that water doesn’t get in and damage the road.
12. Curing
Curing is the method of preventing the concrete slab’s surface from drying out and hardening too quickly. This aids in making sure the concrete hardens correctly and to its maximum strength.
13. Opening of traffic
After the concrete road has sufficiently hardened, it may be used by vehicles. This phase of the build is the last and represents the finalisation of the project.
Concrete road: Advantages
Building roads out of concrete has a lot of benefits for both the roads and the people who use them. Some of the key benefits are:
● Durability
One of the key advantages of concrete roads is their exceptional durability. Studies in the US have shown that the average lifespan of a concrete road is around 34 years, which is double the life of an asphalt road. This means that governments can save millions of dollars in repairs and rehabilitation.
● Comfort
Research has shown that concrete roads provide a more comfortable driving experience. This is because concrete roads are smoother and provide a better surface for driving.
● Performance
Concrete roads offer better performance than asphalt roads. The surface of concrete roads is less likely to slip and skid, and it takes less time to stop on them. Additionally, concrete roads dry faster after rain, providing a safer surface for drivers.
● Application
Concrete roads can be built in many different kinds of weather, but asphalt can only be used when the air temperature is at least 15 °C, and the ground is dry.
● Fuel consumption
Vehicles that drive on smooth concrete roads consume less fuel. Fuel consumption is also affected by how flexible the road is. Heavy vehicles can cause asphalt roads to bend, which increases rolling resistance.
● Reduced pollution
Concrete roads are environmentally friendly, as they are made from natural materials and do not emit pollutants. Asphalt, on the other hand, is made from oil and causes pollution when it is made and when it comes into contact with gasoline, diesel fuel, and other substances.
● Improved visibility
Concrete roads are safer for driving in low light conditions. Being lighter in colour, they absorb less light and provide better visibility at night. Wet weather also makes light reflect better, which makes it easier to see when it’s raining.
● Less deformation
Concrete roads can hold more weight than asphalt roads without deforming as much. This makes them perfect for areas with a lot of traffic.
FAQs
What is a concrete road?
A concrete road is a type of road that is made of concrete, which is usually made of Portland cement, rocks, and water. It is used as a surface for roads, highways, bridges, and other forms of transportation infrastructure.
What are the advantages of a concrete road over an asphalt road?
A concrete road is more durable and comfortable to drive on than an asphalt road. It also performs better, can be used in more ways, uses less fuel, makes less pollution, and doesn't change shape as much.
What is the service life of a concrete road?
The average lifetime of a concrete road is around 34 years, which is twice the physical life of an asphalt road, which is 17 years.
What is the process of constructing a concrete road?
The process of constructing a concrete road involves several steps, including preparing the subgrade, placing the forms, watering the prepared subgrade, batching the materials, transporting and laying the concrete mix, compaction, floating, belting, brooming, edging, joint filling, curing, and opening to traffic.
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