How were setts prevented from spreading outwards? - History of setts

[jaysettpav]

I was wondering how setts were retained before the invention of concrete? I have placed fairly heavy granite kerbs (9kg to 18kg) around the edge on top of sand, sub-base and hardcore. I am trying to avoid the use of concrete so I thought I may be able to gain some inspiration from the construction industry of the past.

I have had a look at your alternative to haunching with concrete. Many seem to require a kind of sub-base where a long peg is hammered in so they don't seem to apply to pounding into soil.

I saw your nice video on laying kerbs by construction workers. You mention concrete in the form of granules poured in with machines and shovels and then the kerbs were placed. This haunch was completed by more of these granules placed around the back of the kerbs. I could only see them compacted by the kerber's shuffle. Have I missed something because it did not look secure at all. Do they add water to this to harden it?

Many thanks for your replies.

[Tony McC]

Granules? That would be the concrete, then! Never heard it refered to as "granules" before.

There have been basic forms of concrete for over 2,000 years although it hasn't always been used for edge restraint. On some of the old, unreconstructed sett-paved roads that still exist - such a sthat going over the Pennines near Littleborough, the edge restraint was formed by using bigger and/or heavier and/or longer "kerbs" at the free edges, and bedding them into gravel or similar and then banking earth against them.

9kg to 18kg really isn't heavy. A basic concrete road kerb (152 x 255 x 915mm) weighs in at around 70kg and the big old granite kerbs we used to lay all around Liverpool would be 3 or 4 times as heavy.