Road Kerbs: Design, Materials, and Types

Kerbs In Roads:

1. The top of the kerbs should be 100 mm above the road surface. With the pavement, the kerb is laid on a concrete bed of at least 100 mm thickness.
2. At least 150 mm to provide lateral support the kerbing should be provided. To the concrete level, kerbs can be tapped.
3. the longitudinal drainage system this type of kerb is beneficial and the height of this type of kerbs is 70 to 80 mm.
4. Commonly most straight kerbs are 915 mm in length but sometimes the small type of kerbs are manufactured as per requirement.
5. In transportation engineering, the radius kerbs are generally 780 mm in length.
6. In the beginning, natural stone was used as kerbs stone but nowadays this has largely been replaced with precast concrete.
7. For severe emergency vehicles, they can climb and be parked on footpath or shoulder.
8. For the longitudinal drainage system, this type of curb is beneficial and the height of this type of kerbs is 70 to 80 mm, and this type of kerbs known as mountable kerbs.

Shape of Kerbs:

1. Kerb is also a vertical or nearly vertical face is called a barrier or non-mountable curb.
2. To discharge the motor vehicle drivers from leaving the roadway.
3. In towns or cities, the square or nearly square kerbs are used.
4. At low speed, the motor vehicle is moved on a sloped kerb.
5. On the suburban thoroughfares, slope face kerb is majorly used.
6. In a certain place like California to achieve a standardized design and construction at low cost using 610 mm gutter that balanced the initial and maintenance cost.
7. The high containment kerbs are used in great Britain in a location with pedestrian, fuel station pumps, and other areas where they need greater protection from vehicle traffic.
8. To reducing the coast there are also used to eliminate the need for driveway cuts, kerbs, and aprons.
9. To the driveways, the rounded kerbs are mostly used where the continuously along suburban residential streets are many driveways and sidewalk has a grassy from the street.
10. This type of kerns is generally used in flat roads or areas.

Materials of Kerbs in Roads:

1. Kerbs are constructed with many materials like asphalt, the stone of masonry blocks, etc but now a days Portland cement is mostly used for construct the kerbs.
2. The type of materials depends on the nature and purpose of the road.
3. Provide a highly visible barrier at the edge of the road surface Portland concrete kerb with asphalt concrete road is used.
4. The concrete kerb is constructed by setting form by hand, filling them, letting them set up, and removing the forms.
5. If the requirements of concrete kerb are large then to full fill the requirement slip machine is used.
6. By the paving machine, the asphalt kerb is made.
7. The asphalt kerb is cheaper than the concrete kerb if it is made at the same time when the road is paved.
8. But the asphalt kerb is less durable than the concrete kerb.
9. By the granite, the stone kerbs are made. It is more durable and has more resistant power than the other kerbs.
10. For aesthetic reasons, it is generally used.
11. The disadvantage of the granite kerbs is when they cut a tire sidewall if it is the rough face.
12. These kerbs are vertical or angle to create a mountable kerb.

Kerb Height:

1. When an engineer designs a road kerb then specify the reveal or lip. The height of the section is known as a reveal that is visible above the road surface.
2. The range of typical road kerbs is 4 to 8 inches or 100 to 200 mm.
3. For the accommodate automobile design, the recommendations have been used 4/12 better.
4. Because the steeper batter tends to interface with body trim and lower door edge while kerb face in excess 152 mm in height.
5. To improve the kerb stability most kerbs are extended down into the ground below the pavement surface.
6. 16-inch should be the total height of the kerb including the buried portion.

What Is Kerb Stone?

The kerbs stone is generally used in the edge of the carriageway or footpath.

1. By the granite, the stone kerbs are made. It is more durable and has more resistant power than the other kerbs.
2. For aesthetic reasons, it is generally used.
3. It has some disadvantage of the granite kerbs is when they cut a tire sidewall if it is the rough face.
4. These kerbs are vertical or angle to create a mountable kerb.

Materials of Kerb Stone:

1. Many different types of cement are used in kerbs stone construction.
2. That’s are ordinary Portland cement, rapid herding cement, low heat Portland cement, Portland slag cement, Portland pozzolana cement, and super sulfated cement, etc.
3. There are all grades of aggregate are used. But the aggregate impact value, crushing value, and abrasion value should not be exceeded the following requirements.
4. Nowadays an alternative coarse aggregate blast furnace slag is used in construction in stone kerbs.
5. That has more sulfate resistance power from kerbs stone.
6. And this type of kerbs shall not absorb more than 10 percent of the water of its mass.
7. The grade concrete that is used in stone kerb construction shall not be less than M20 grade and high strength is required.

Types of Kerbs:

There are four types of kerbs:-

1. Low or Mountable Kerbs.
2. Low-Speed Barrier or Urban Parking Kerbs.
3. High-Speed Barrier Kerbs.
4. Submerged Kerbs.

#1. Low or Mountable Kerbs-

1. The low or mountable kerbs are also known as class I kerbs. The main principle of the kerbs is to control traffic to stay within its lane.
2. To provide facilitates the driver to enter the area of the shoulder with less difficulty the height of this form of kerb is low.
3. For the longitudinal drainage system, this type of kerb is beneficial and the height of this type of kerbs is 70 to 80 mm.

#2. Low-Speed Barrier or Urban Parking Kerbs-

1. The low-speed barrier or urban parking kerbs is also known as class II kerbs. To the footpath to prevent encroachment of slow speed or parking vehicles.
2. For severe emergency vehicles, they can climb and be parked on footpath or shoulder.
3. To avoid the scraping of tires the height of this type 0f kerbs is 150 to 200 mm.

#3. High-Speed Barrier Kerbs-

1. The high-speed barrier kerbs are also known as class III kerb. In the bridges, mountains, or where the path is critical there the high-speed barrier kerbs are used.
2. The height of this type of kerbs is lies between 230 to 450 mm or more.

#4. Submerged Kerbs-

1. The submerged kerb is also known as class IV kerb. This type of kerbs is also provided in rural roads at pavement edges between edges and shoulders.
2. To provide lateral stability to the granular base course and flexible pavements.
3. In the form of standing bricks or concrete blocks, it is provided.

Road Kerb:

Road kerbs are the most essential things in the transportation system and it provides the following purposes-

1. Between the footpath and pavement, it acts as a boundary wall.
2. The road kerb prevents the vehicle from parking beside the road.
3. To the pavement, the kerbs provide structural support.
4. To overcome the slipping risk of the vehicles it helps.
5. To reduce the number of accident its help.
6. For drainage purposes, it is also used.
7. To provide lateral stability to the granular base course and flexible pavements
8. This type of kerbs is also provided in rural roads at pavement edges between edges and shoulders.

Road Kerb Details:

1. Kerbs is an edge where a raised sidewalk or road median meets a Street or other roads.
2. Kerbs are constructed with many materials like asphalt, the stone of masonry blocks, etc but now a days Portland cement is mostly used for construct the kerbs.
3. The asphalt kerb is cheaper than the concrete kerb if it is made at the same time when the road is paved.
4. There have many numbers kerbs that are categorized by shape, high, material, and where the kerb is combined with a gutter.
5. From the pavement, most kerb is constructed separately and at the joint, the gutter is formed between the roadway and the curb.
6. Generally, most straight kerbs are 915 mm in length but sometimes the small type of kerbs are manufactured as per requirement.
7. In the beginning, natural stone was used as kerbs stone but nowadays this has largely been replaced with precast concrete.

FAQ: Road Kerbs

What Is the Standard Height for Kerbs Above the Road Surface?

The standard height for the top of the kerbs is 100 mm above the road surface.

What Materials Are Commonly Used for Constructing Kerbs?

Kerbs are constructed using various materials, including asphalt, natural stone, masonry blocks, and Portland cement. Precast concrete is widely used nowadays.

What Are the Different Types of Kerbs Used in Road Construction?

There are four main types of kerbs:

1. Low or Mountable Kerbs (Class I)
2. Low-Speed Barrier or Urban Parking Kerbs (Class II)
3. High-Speed Barrier Kerbs (Class III)
4. Submerged Kerbs (Class IV)

What Is the Purpose of Low or Mountable Kerbs?

Low or mountable kerbs are designed to control traffic and facilitate drivers’ access to the shoulder with minimal difficulty. They are beneficial for longitudinal drainage systems.

How Are High-Speed Barrier Kerbs Used?

High-speed barrier kerbs are used on bridges, mountainous regions, and critical paths to provide a barrier for high-speed vehicles. Their height ranges from 230 to 450 mm or more.

Why Are Granite Kerbs Used, and What Is Their Disadvantage?

Granite kerbs are used for their durability and aesthetic appeal. However, they can cut tire sidewalls if they have a rough face.

How Does the Height of a Kerb Affect Its Functionality?

The height of a kerb, known as the reveal or lip, affects its visibility and its ability to prevent vehicles from leaving the roadway. The typical height ranges from 100 to 200 mm.

What Are the Benefits of Using Portland Cement for Kerbs?

Portland cement provides a highly visible barrier at the road edge and offers durability. It is commonly used with asphalt concrete roads.

What Is the Role of Kerbs in Road Safety?

Kerbs act as a boundary between the footpath and pavement, prevent vehicles from parking beside the road, provide structural support to the pavement, reduce slipping risks, and help in drainage, thereby reducing the number of accidents.

How Are Concrete Kerbs Constructed?

Concrete kerbs are constructed by setting forms by hand, filling them with concrete, allowing them to set, and then removing the forms. For large-scale requirements, slip machines are used.

What Is the Difference Between Low-Speed Barrier Kerbs and High-Speed Barrier Kerbs?

Low-speed barrier kerbs (Class II) are used in urban areas to prevent slow-speed or parked vehicles from encroaching on the footpath, with a height of 150 to 200 mm. High-speed barrier kerbs (Class III) are used in high-speed areas like bridges and mountainous regions, with a height of 230 to 450 mm or more.

Why Are Submerged Kerbs Used, and Where Are They Typically Installed?

Submerged kerbs (Class IV) provide lateral stability to the granular base course and flexible pavements. They are typically installed in rural roads at the edges between the pavement and the shoulder.