An expansion joint is installed “in a building structure or concrete work, a joint or gap between adjacent parts that allows for safe and inconsequential relative movement of the parts, caused by thermal variations or other conditions,” defined by dictionaryofconstruction.com. This construction material is not put randomly or wherever the contractor sees it fit. It requires to be calculated and what we mean by the word ‘calculated,’ an equation is needed to be solved. Every calculation must be accurate because a miniscule displacement could cause monumental damage.
The importance of expansion joints is best described based on its application or where it can be used. In general, it strengthens the structural integrity of a building, bridge, pavement, wall, and ceiling. Expansion joints are unnoticeable and sometimes we are not aware that we’re already walking on or looking at them. Below is the detailed use of expansion joints:
Bridges
In the Philippines, the Department of Public Works and Highways issued guidelines on how to use expansion joints in bridges under Department Order No. 85. It is stated there that “expansion joints for bridges are designed to provide for continuity between two parts of the structure which are in relative movements because of thermal deformations, creep, shrinkage and displacement/deflection of the structure under traffic load.” Bridges can be likened to a bow in that it bends when a truck or bus passes over it. It can be swayed by wind or, in extreme conditions, by an earthquake. By installing expansion joints, it makes rigid structures such as bridges, be more ‘flexible.’
Buildings
Rappler reports the possible damage on buildings the moment a 7.2 magnitude earthquake strikes Metro Manila. The residential buildings that could be heavily damaged are 168,300 (12.7%). Out of the 981 mid-rise buildings with 10-30 stories high, 11% could be heavily damaged. The high-rise buildings with 30-60 stories high that could be heavily damaged are about 12% out of 119 properties. This is a chaotic scenario that can be prevented by proper construction practices such as applying expansion joints not just in Metro Manila building but on every structure built in the Philippines. It is commonly applied on walls, roof, and ceiling.
A typical example would be tile flooring which can be subjected to expansion and contraction due to temperature changes. There is then a need to install expansion joints but there are factors to consider. The Quick Step says “the maximum floor length you can install without expansion joint mainly depends on two things: (1) the shape of the room; and (2) the climate conditions in that room.”
image source: reddit.com
In the Philippines, the Department of Public Works and Highways issued guidelines on how to use expansion joints in bridges under Department Order No. 85. It is stated there that “expansion joints for bridges are designed to provide for continuity between two parts of the structure which are in relative movements because of thermal deformations, creep, shrinkage and displacement/deflection of the structure under traffic load.” Bridges can be likened to a bow in that it bends when a truck or bus passes over it. It can be swayed by wind or, in extreme conditions, by an earthquake. By installing expansion joints, it makes rigid structures such as bridges, be more ‘flexible.’
Buildings
Rappler reports the possible damage on buildings the moment a 7.2 magnitude earthquake strikes Metro Manila. The residential buildings that could be heavily damaged are 168,300 (12.7%). Out of the 981 mid-rise buildings with 10-30 stories high, 11% could be heavily damaged. The high-rise buildings with 30-60 stories high that could be heavily damaged are about 12% out of 119 properties. This is a chaotic scenario that can be prevented by proper construction practices such as applying expansion joints not just in Metro Manila building but on every structure built in the Philippines. It is commonly applied on walls, roof, and ceiling.
Flooring
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| image source: emseal.com |
Piping
Expansion joints can be seen in piping systems as well, and it is commonly known as bellows. According to ORK-Flex, these “joints absorb axial displacement of piping caused by changes in temperature, lateral displacement and angular displacement… Combinations of expansion joints can be used as earthquake-proof piping for seismic isolated structures.”
Expansion joint is one of the solutions that can be used for earthquake-proofing buildings in the Philippines. However, due to budget limitations we have to create alternative doable ways to prevent the ‘Big One’ from doing so much damage. The ‘Big One’ is when a 7.2 magnitude earthquake shakes Metro Manila and its nearby provinces because of the West Valley Fault. In an article on Rappler, it is estimated there will be 33,500 casualties and 113,600 wounded, this is according to a Metro Manila Earthquake Impact Reduction Study (MMEIRS) conducted by Philvocs, the Metropolitan Development Authority (MMDA) and the Japan International Cooperation Agency (JICA) in 2010. As a refresher course, a 2nd Metro Manila Shake Drill and 2nd Nationwide Simultaneous Earthquake Drill (NSED) will happen this June 22 at 9 am. We’re not going to do this because we are anticipating it to happen but because it is inevitable and we must be ready to face it when that time comes.
Expansion joints can be seen in piping systems as well, and it is commonly known as bellows. According to ORK-Flex, these “joints absorb axial displacement of piping caused by changes in temperature, lateral displacement and angular displacement… Combinations of expansion joints can be used as earthquake-proof piping for seismic isolated structures.”
Expansion joint is one of the solutions that can be used for earthquake-proofing buildings in the Philippines. However, due to budget limitations we have to create alternative doable ways to prevent the ‘Big One’ from doing so much damage. The ‘Big One’ is when a 7.2 magnitude earthquake shakes Metro Manila and its nearby provinces because of the West Valley Fault. In an article on Rappler, it is estimated there will be 33,500 casualties and 113,600 wounded, this is according to a Metro Manila Earthquake Impact Reduction Study (MMEIRS) conducted by Philvocs, the Metropolitan Development Authority (MMDA) and the Japan International Cooperation Agency (JICA) in 2010. As a refresher course, a 2nd Metro Manila Shake Drill and 2nd Nationwide Simultaneous Earthquake Drill (NSED) will happen this June 22 at 9 am. We’re not going to do this because we are anticipating it to happen but because it is inevitable and we must be ready to face it when that time comes.
This article is brought to you by: GCK
