What is a Concrete Expansion Joint?
Concrete expands and contracts as it changes temperature. Cracks may form if these changes aren’t managed, leading to a weaker and less attractive concrete.
Expansion joints are a common solution to this problem. In this article, find out what expansion joints are, how they work and how they’re used.
What are expansion joints?
A concrete expansion joint is a small gap that provides space for the concrete to expand and contract. It is placed between the concrete and whatever the concrete abuts, allowing independent movement between these structures.
Expansion joints also absorb vibrations and permit soil movement as a result of earthquakes.
Essentially, expansion joints allow for thermal expansion and contraction without inducing stress. By reducing stress within the concrete, expansion joints prevent cracks from forming.
Do I need expansion joints?
Expansion joints are important for preventing cracks within concrete. Concrete is most susceptible to cracks after being poured, because it shrinks slightly as it dries, and then expands or contracts depending on the ambient temperature.
Expansion joints are only required when the concrete meets another structure. This might be a building or another slab of concrete. Expansion joints are usually placed at the end of the day or when the concrete pour has halted for longer than the initial setting time of concrete.
Remember — cracks in the concrete can weaken the whole structure. If you’re constructing a bridge or building, it’s crucial to prevent cracks from forming.
Where might you use expansion joints?
Expansion joints can be found in a variety of concrete structures, including:
- Railway tracks
- Piping systems
- Concrete roads
How do I install expansion joints?
Here are some tips for using expansion joints:
- Space the joints apart by around 30x the thickness of the slab
- Cut the joints as deep as at least a quarter of the thickness of the slab
- Cut the joints within 12 hours after pouring the concrete
- Where possible, strategically place the joints under walls to hide them from view
At Total Concrete, we help you complete your concrete projects by providing QSRMC-certified concrete mixed to your requirements. We have a range of strengths and blends available, and we can even mix the concrete on your site to ensure you receive the exact amount you need.
So whether you’re in need of concrete for a small home renovation or require commercial concrete for a construction project, we can help. Serving customers throughout Woking, Surrey and Guildford, we have everything you need to get started.