Box Culvert Vs. Slab Culvert
learn about the difference between box culvert and slab culvert in this article.
What Is Box Culvert?
A culvert having one or more square or rectangular openings, and its floor and top slabs are monolithically constructed with abutments and a pier, is referred to as a box culvert.
What Is Slab Culvert?
The culvert, in which the superstructure consists of an RCC slab that carries the bridge floor, is called a slab culvert. It is also known as a bridge culvert.
Now let’s check their differences in detail.
Difference Between Box Culvert & Slab Culvert
|Box culvert generally consists of one or more numbers of box tunnels placed side by side. The top serves as the roadway.
|The slab culvert has its superstructure consisting of a series RCC slab that carries the bridge floor, and a pavement surface is placed on top to provide a road.
|They are four-sided rectangular or square structures, the lower side pressed into the ground below.
|In the case of slab culvert, there will be rcc deck slab laid over abutments. They can be can also be three-sided.
|The size of a box culvert for single span is normally 3 m and for double span is 6 m.
|Slab culverts can be up to a maximum span of 3 m.
|It is usually constructed of precast RCC slabs. Small span box culverts may be constructed of stone slabs, supported on masonry abutments, with brick or stone flooring.
|In slab culvert, the RCC slab of suitable thickness is provided as simply supported over abutments and piers which are constructed of any suitable type of masonry.
|The velocity of the water flow might be changed due to the bottom slab.
|Slab culverts do not consist of bottom slabs, so natural water flow is maintained and natural bottom substrata remain unaffected.
|The sharp edges of the box-shaped slabs affect the vehicle speed and restrict them from running at high velocity.
|Slab culverts do not have sharp corners hence making them suitable for vehicles running at high speed.
|These culverts provide the least interference to traffic during construction.
|Slab culverts do not allow traffic during construction. Require sufficient time for setting of concrete.
|Earth pressure is the main force in the case of box culverts.
|IRC Loadings have to be taken into account while designing the slab culvert.
|Standard design: ASTM C 1433
|Standard design: ASTM C 1504
|This type of culvert is required for purposes that require artificial flooring.
|Slab culverts can replace box culverts if no artificial flooring is necessary.
|Box culverts are mainly constructed where the soil is soft and the load has to be distributed over a wider foundation area.
|Slab culverts are suitable where the bed of the canal or stream is sufficiently firm.