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Tarmac breaking up

Tarmac is breaking up and looks like crazy paving in places its also sinking in places. What could be causing this to happen?

2 Answers from MyBuilder Driveway Pavers

Hi, there are many possibilities causing the tarmac to break up
1) incorrectly compacted during installation there for creating weak spots with in the layer
2) the layers of tarmac were installed too thinly and tarmac will wear away/crumble over time
3) vehicular movement - if the tarmac that is bad is in an area where there is much breaking and/or turning then over time this can/will create forced acting on the tarmac that is always pushing in a given direction - like kneading out dough!
4) age of tarmac - good, well laid tarmac could possibly have a life span of 15 years. In time it becomes brittle and breaks up
5) weather - tarmac is malleable - it softens in higher temperatures which causes expansion and with traffic movement will move more ie thinner in places thicker in the other. And when cooling it will never fully retract to original quality - this linked with any of the above are all factors
Also there is freeze thaw action - common with concrete and referred to as concrete cancer, it also evident in brick work and block work - any hard material really! It is when moisture/rain/water gets into cracks or breaks within a hard material, sits there and freezes. once frozen it can expand, when it thaws it retracts. But the constant expansion/shrinking cycle causes the material to weaken until the freezing action actually "blows" the material. and a material is only as strong as its weakest part. once this happens it opens the flood gates to more water inlet and more blowing, its a chain reaction

Hope this helps

P.S. regarding the sinkage underneath - there could be voids being created under the fill material, maybe a water leak under ground or previously improper compaction of sub base


Answered 26th Apr 2017

Could be anything above I totally agree


Answered 16th Jun 2017

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