Difference Between Box Culvert And Slab Culvert (Explained in Detail)

Looking for the difference between box culvert and slab culvert? Here we have explained the difference between them in points that will help you understand easily.

A small bridge which is 6m in length or less, between the faces of abutments that is what engineers called a culvert. 

A culvert is a permanent structure of drainage to carry a roadway or railway track on small streams.

Difference Between Box Culvert And Slab Culvert

Slab culverts and box culverts are two distinct types of culverts. To pick between these two culverts a specialist should know the differences between them. 

The principal difference between box culvert and slab culvert is given below. 

Box Culvert 

  • Box culverts are four-sided rectangular structures, the lower side squeezed into the ground beneath, the top filling in as the street and the parallel sides upheld by the dirt on one or the other side of the obstacle. 
  • The ordinary size of the boxes is 3’x2′ or 12’x12′ in the 1′ range and the risk increases. (Typically comes in lengths of 6′ and 8′) 
  • A box culvert might be built with a solitary box, or various box cells set next to each other. 
  • Standard plan: ASTM C 1433 
  • The speed of streaming water may change given the base slab. 
  • The sharp corners of the box-molded slabs make it inadmissible for vehicles running at high speed. 
  • Box culvert is needed for purposes that require counterfeit ground surface. 
  • It tends to be utilized for water removal and waste, thus it probably won’t be utilized in dry seasons. 

Slab Culvert 

  • Slab culverts, otherwise called connect culverts, can be three-sided, or just a deck slab implanted in the dirt on one or the other side, giving a scaffold over the distance. 
  • Generally, a progression of slabs is laid to shape an extension-like structure, and an asphalt surface is put on top to fill in as the street. 
  • The standard range length goes from 8′ to 48′. 
  • Standard plan: ASTM C 1504 
  • Slab culverts don’t have base slabs, so the common progression of water is kept up and the normal base substrate stays unblemished. 
  • Slab culverts have no sharp corners to influence the security of high-speed vehicles. 
  • Slab culverts can supplant box culverts if no fake ground surface is essential. 
  • It gives getting-over little streams and actual blocks.

Types of Culverts: 

Culverts are grouped into the accompanying four types: 

1. Arch Culvert. 

2. Open or Slab Culvert. 

3. Pipe Culvert. 

4. Box Culvert. 

1. Arch Culvert: 

The culvert having its superstructure consisting of a couple of arches developed of any reasonable stonework is known as an arch culvert. 

In these types of culverts, segmental arches consisting of block workmanship, stonework, or cement are usually utilized. These arches can be effectively and efficiently built. 

The projections and docks or these arches are developed adequately solid to take their sidelong push Arch culverts are particularly reasonable where the methodologies are to be built in cutting. 

2. Slab Culverts: 

The culvert, having its superstructure consisting of an RCC slab that conveys the extension floor, is known as a slab culvert. 

In this sort of culvert, the RCC slab of appropriate thickness is given as basically upheld over projections and docks which are developed of any reasonable kind of stonework. 

Slab culverts are reasonable where the bed of the waterway or stream is adequately firm. These are given up to a most extreme range of 3 m. 

3. Pipe Culvert: 

These types of culverts consist of at least one pipe set one next to the other over a solid base beneath the bank of a street or railroad track. 

In this kind of culvert, at least one pipe consisting of cast iron, steel, or RCC is held in a situation over a solid base by fixing the two finishes into workmanship dividers. In pipe culverts, for the most part, more than one pipe, of breadth at least 30 cm is utilized. 

In any case, their precise number and breadth relying on the release and tallness of the bank. Quite far the angle of the pipe ought not to be under 1 of every 1000. Pipe culverts are reasonable where the progression of water in the stream is little. 

4. Box Culvert: 

The culvert, comprising at least one quantity of rectangular or square openings, having its floor and top slabs built solidly with projections and wharf, is known as a box culvert. 

Box culvert is typically built of precast RCC slabs. Little range box culverts might be developed of stone slabs, upheld on workmanship projections, with block or stone ground surface. These culverts give minimal impedance to traffic during construction. 

Box culverts are mostly built where the dirt is delicate and the heap must be disseminated over a more extensive establishment region. This kind of culvert can be traditionally utilized for a solitary range of 3 m or a twofold range of 6 m. 

For more details, let’s discuss the types and their benefits below.

Types of Culvert for Drainage

1. Corrugated Steel Pipe

This steel pipe culvert is made of steel pipe material that has a corrugated shape.

Its function is not only to become a waterway but also to access roads for humans and vehicles.

The advantages of corrugated steel pipe tunnels are their low price and easy construction process.

The period of use for the tunnel is quite long, which is 25 years.

2. Polyvinyl Chloride

This type is made of polyvinyl chloride or PVC plastic.

Its use is used in narrow and small areas and does not require large load pressures.

This type of PVC is more suitable for the drainage of residential areas.

3. Concrete

This type of one culvert is most widely used for large areas that require high load resistance.

The process is done on the spot, but not a few have come in precast form from the factory.

Its dimensions follow the functional requirements and the water discharge that needs to be accommodated.

The concrete tunnel has its own type.

Here are the kinds.

Concrete Buis

The concrete tunnel is the oldest type among other types.

This type was first introduced by foreign companies in 1984.

Before advanced technology was invented, concrete bushing tunnels were made using circular molds.

Now, the chunks are sent directly from the factory, making the building process easier.

Reinforced concrete pipe buis in the shape of a perfect circle.

The diameter is 20-150 cm with a length ranging from 50-100 cm.

The function of the concrete culvert is to provide a way for planted drains.

Typically, these concrete tunnels are installed under roads with heavy stress, such as tolls or highways.

Apart from being a water channel, this type is also used for building foundations, infiltration wells, septic tanks, and pot substitutes.


The U-Ditch culvert is a concrete tunnel that has an open surface, thus forming a U.

They are larger than concrete buis and are used for waterways in housing and roads.

This one type has a separate cover.

Its feature makes it easy for us to open and close the concrete channel if there are problems or are in the process of inspection.

Not only that, but the separate cover also simplifies the cleaning process.

Box Culvert

Just as the name suggests, this type of concrete tunnel is rectangular in shape.

The material is thick so it is suitable to be used to withstand large loads.

The culvert box has two parts, namely the socket and the spigot.

The two parts function to connect each component so that it is firmly attached.

Because of their thick material, box culverts can be built either below or above ground level.

This type is used for many things, including vehicle tunnels, bridges, waterways, and underground passages.

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