Dating Technique

cfuserkildare

Hey folks,

I am trying to find out if there is any easy way to date concrete.

I found a piece stone that initially was thought to be from a fireplace, had that pumice sort of look to it.
However it turns out that it is a lump of concrete.

Was found near a Motte that has a hole dug in the side by rabbits.

Anyone have any ideas about dating it?

Thanks.

Society might frown upon your relationship, but don't let that discourage you.

Sorry... I couldn't resist!

cfuserkildare

Ha Bleedin' Ha,

What happens in a Motte, Stays in a Motte!!!

tac foley

Well, the first documented modern use of what we would call mass concrete took place in France, when the Canal du Midi was built around 1667 - 81.

See - http://en.wikipedia.org/wiki/Canal_du_Midi

A revival of interest in concrete in the 18th century occurred when engineers and scientists began to experiment with new cements culminating in the development of Portland cement by Joseph Aspdin and later by Isaac Johnson.

In the early 19th century concrete began to be used extensively in houses, generally as un-reinforced mass concrete, clad or rendered in other materials.

tac

slowburner

cfuserkildare wrote: »

Hey folks,

I am trying to find out if there is any easy way to date concrete.

I found a piece stone that initially was thought to be from a fireplace, had that pumice sort of look to it.
However it turns out that it is a lump of concrete.

Was found near a Motte that has a hole dug in the side by rabbits.

Anyone have any ideas about dating it?

Thanks.

Could it be lime mortar?

cfuserkildare

I have a couple of pictures, not great quality but might be enough for somebody that knows they're stuff.

slowburner

Not so sure that it is concrete. It could easily be a piece of lime mortar attached to a stone. It could also be a natural conglomerate stone.
Might get a better answer if you post it up in the Geography forum.

cfuserkildare

Hi Slowburner,

I don't think it is natural, the photo's do not show it too well, but the lighter areas are slightly lighter in colour than Pumice.

The reason it caught my attention was the fact that it looks like it was part of a fireplace, has that look as though it has been exposed to heat over a long period of time.

If that helps any.

cfuserkildare

Hey Slowburner,

What sort of period would Lime Mortar date from?

It seems like it might be as you suggested.

The item was found near a Motte which just happens to be on the site of a previous earthwork from around 200AD.

There are a few pieces of stone which look cut and shaped that appear to have been dug out of a hole by a rabbit.

cfuserkildare

Just as point of interest, how heavy would Lime Mortar be?

slowburner

cfuserkildare wrote: »

Hey Slowburner,

What sort of period would Lime Mortar date from?

C12th, at the earliest. Your example - if it is a lime mortar - looks much later than that though, perhaps as late as the C18th.

cfuserkildare wrote: »

Just as point of interest, how heavy would Lime Mortar be?

That varies with the aggregate content but it should be quite a bit lighter and more friable than concrete.

Maudi

cfuserkildare wrote: »

I have a couple of pictures, not great quality but might be enough for somebody that knows they're stuff.

Id have limited experience in lime mortar and had the pleasure of seeing it produced I dont think however this is it..seems to me theres small pieces of white quartz in your sample. .which I dont think would be in lime mortar..part of the process involves crushing everything to dust you see..however I have come across similiar pieces of the "concrete" type material in a quarry near me and was puzzelled how it got there til a local geologist explained that it was a natural conglomerate. .

Maudi

cfuserkildare wrote: »

I have a couple of pictures, not great quality but might be enough for somebody that knows they're stuff.

Id have limited experience in lime mortar and had the pleasure of seeing it produced I dont think however this is it..seems to me theres small pieces of white quartz in your sample. .which I dont think would be in lime mortar..part of the process involves crushing everything to dust you see..however I have come across similiar pieces of the "concrete" type material in a quarry near me and was puzzelled how it got there til a local geologist explained that it was a natural conglomerate. .