Expansion joints

[Johnmelad502]

Got this from a website which is fairly self explanatory except, what is an expansion joint and how is it made? Cheers

Driveways and Parking areas

•The thickness of the concrete - 125mm (5 inches) for family sized car or 150mm (6 inches) for light vans etc.
•The thickness of the sub-base - 150mm (6 inches).
•The slope of the concrete - 1 in 40 (25mm in 1 metre, 1in in 3 ft) for driveways, 1 in 60 (16mm in 1 metre, 5/8in in 3 ft) for parking area.
•The need for any expansion joints - every 4 metres (13 ft).

 

[Shytalkz]

EJS are not required every 4m.

For differing joint type explanation, see p30 et seq, here.

 

[Johnmelad502]

What exactly are expansion joints in this context and how are they made?

 

[noseall]

Expansion joints are gaps in concrete or masonry.

They would perform best if they were fresh air, but troublesome visitors like water, germinating seeds, small animals will invariably find there way in and cause trouble.

So these gaps are pumped with polysulphide mastic or filled using compressible material, i.e. fibreboard, cork etc.