Difference between Construction Joint and Expansion Joint (Explained)

Here in this article we have mainly focused on the Difference between Construction Joint and Expansion Joint. As we all know Joints are interfacing two unique components (Joints)  into one component. 

However, you may be mindful that the weakest zone of a structure is “Joint”  so if conceivable keep away from it. 

The greater part of the construction components is framed by various materials and due to weather conditions that may recoil or expand. 

Various kinds of joints are utilized to keep the solid breaks from occurring by the climate condition. 

Today We will talk about the various kinds of joints utilized in construction works. 

Difference between Construction Joint and Expansion Joint

Classification of Joints in Construction

  • Construction Joints 
  • Expansion Joints 
  • Contraction Joints 

We can’t pour a bigger amount of cement at some random time. So around then, a specific part has poured according to the suggested covering plan and the leftover segment will be poured after a specific period. 

In that, the construction joints are utilized to associate the old and new concrete and it is additionally called cold joints. 

Difference between Construction Joint and Expansion Joint 

Construction Joints 

The existing cement ought to have a lopsided surface and liberated from dust. 

An appropriate vibration must be done to approach the joint to build up the legitimate connection between the old and new concrete. 

After pouring of new cement the joint surface should be wiped out lat and slurry by the wire brush. 

The construction joints are given as per IS 11817. 

The construction joints are prudent to evade on the off chance that it is beyond the realm of imagination, at that point lessen the quantity of construction joints. 

Expansion Joints 

As we talked about, the construction materials are shaped from various crude materials. The solid may contract or expand because of the climate condition. 

To keep away from any underlying disappointment in view of the distortion of construction materials, we use expansion joints. 

The expansion joints holes are given to oblige the development occurring by the expansion or shrinkages and it is dodging the disfiguration of the structure. 

Generally the expansion joint holes are giving in enormous structure and scaffold support to spread possible pressure. The joint holes are filled by the expansion material like fiber, bitumen, or some other exceptional material. 

Get to know Expansion Joints, Concrete Connections on Bridges

Talking about the parts of bridge construction, expansion joints are an integral element. Also known as expansion joints or dilation covers, this part has an important function for a bridge. Without expansion joints, the bridge may not function or even endanger the vehicles crossing it.

The expansion joint works by following the horizontal movement of the bridge when it is crossed by a vehicle or when expansion and shrinkage loads occur. This joint can also provide space for the elastomer of the bridge. There are several types of expansion joints that are used for different purposes.

Before discussing further about expansion joints, you first need to know what an expansion joint is. Broadly speaking, an expansion joint is a type of connection used to connect concrete to a bridge construction. With this connection, vehicles can safely cross the bridge.

Expansion joints are commonly installed on two areas of concrete floors or rigid pavements. However, expansion joints are most commonly used in a bridge construction. This part can be seen easily with the naked eye. Expansion joints usually stand out as a connection on asphalt roads or bridges.

The way an expansion joint works is to follow the horizontal bridge movement that occurs as a result of a passing vehicle or an expansion and shrinkage load on the bridge. With this movement, the joint provides a vertical space that arises due to the compressive force of the bridge bearings (elastomer). 

In its application, the expansion joint usually uses a seal specially designed to join the bridge. Seals are usually used to fill the parts between joints so that they can function optimally. In addition, the seal is also a material as a function of water channels, in order to protect the sub-structure from the presence of water which allows concrete corrosion. 

In addition to seals, there are also special steel profiles that are used as locking and gluing seals, as well as anchors that are used for structural strengthening and for joining the reinforcement from the slab to the steel profile.

Even though it seems simple, the expansion joint on the bridge turns out to have such a big function. Since the bridge will be crossed by various types of vehicles with different tonnages, coupled with the extreme weather that may arise, the joints on the bridge serve to accommodate the movements that occur in the bridge superstructure.
This movement can be caused by live loads, the physical properties of the bridge-forming, to changes in temperature that cause expansion and shrinkage. In addition, the function of the expansion joint is to reduce vibrations that may arise due to loads on the bridge surface.

Expansion joints are also an effort to maintain the shape of the bridge structure. Due to several factors previously mentioned, the bridge may undergo a change in shape. With expansion joints, the bridge is better prepared to accept loads and accommodate the movements that arise.

The expansion joints on the bridge are of several types. Each type has different characteristics and uses. However, according to the Florida Department of Transportation, expansion joints are divided into two types, namely open connections and closed connections.
As the name implies, a closed joint is a connection in which the expansion joint will be closed so that it is waterproof. Meanwhile, open joints do not have a cover so they are open and not waterproof. To find out more about the types of expansion joints, here is a general discussion that you need to know:

1. Open expansion joints

This type of expansion joint uses a drainage system which is usually placed at the bottom of the joint. This is because the open connection allows water to penetrate into the connection. To avoid water dripping from the top of the bridge, a drainage system was created to collect and carry water to disposal.
The drainage system in open expansion joints is usually made of stainless material and is trough-shaped. Open expansion joints can be further divided into two, namely butt joints and finger joints which have many gaps. Each of them has a different function and use.
For example, butt joints can be used on bridges with less motion, with a maximum gap of 25 mm. Butt joints are no longer used in western countries because they are not waterproof. Meanwhile, Indonesia still uses this type of connection, especially on bridges with spans that are not too long.
Meanwhile, finger joints that have many gaps resemble fingers that meet each other. Since it is an open joint, a drainage system is required at the bottom of the joint. Finger joints are usually made of steel plates.

2. The expansion joint is closed

This type of expansion joint is widely used in Indonesia. As the name implies, a closed expansion joint uses a cover called a seal. Seals for closed expansion joints are of several types, from rubber to binder materials. Because it uses a closed system, this connection does not require a drainage system at the bottom of the bridge.

Closed expansion joints are divided into four types, namely compression seal expansion joints, asphaltic plug joints, strip seal joints, and modular joints. Each type of connection has different characteristics and different uses.

For example, the compression seal expansion joint uses a rubber material as a seal. Meanwhile, the asphaltic plug joint uses binder, anchor and steel plate as a filler in the bridge connection. Meanwhile, elastomer and iron are used in strip seal joints.

An expansion joint is a connection commonly used in a bridge construction. This connection has a very large function, namely ensuring the safety of the bridge structure. The expansion joint itself has various types that can be used as needed.

Detail 

Expansion joints may be given in the middle of each range in scaffolds. 

The arrangement of expansion joints is the point at which the structure length exceeds  45m. 

The fortifications ought not be given on the expansion joint region. 

The expansion joint material will be distinctive dependent on the structure. 

The expansion joints are given as per IS 3414. 

Compression Joints 

It is another sort of joint which controls the breaks occurring because of shrinkages. The withdrawal joints are put as a section where the break may frame in cement.

Also checkout: Deep Foundation Meaning, Types and Uses

On the off chance that the shrinkage break is framed in the solid chunk, at that point the constriction joints forestall spreading on the other territory. 

Particular 

The width of the score ought not be under 5mm. 

The constriction joint profundity is 1/fourth of the Concrete mean profundity. 

It ought to be put in the most vulnerable zone of the chunk. 

Another name of the withdrawal joint is Control Joint. 

We trust you may get lucidity about the various kinds of joints in construction.

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