I have just read that Genesis mentioned the Tower of Babel being described as having "tar for mortar". I've never before heard of something as sticky and viscous as tar being used as mortar, but evidently, it was the material of choice for the Sumerians to put together their oven-baked bricks (themselves more durable than regular sun-baked bricks).
On a related note, the Romans invented concrete, which was also used to make mortar. But unlike modern concrete, or Portland cement, Roman concrete used volcanic ash as an aggregate. Using volcanic ash, the concrete gets harder as it gets older and it is even guaranteed to be waterproof. This is how the structures of the Roman Empire stood for the past 2,000 years whereas modern buildings aren't expected to last longer than 150 years in a Life After People.
So imagine that there was an ancient culture who used the following ingredients to make their mortar:
- Powdered limestone
- Water (usually <40%)
- Volcanic ash
Would the recipe above make a good mix? Or would the addition of tar make the mixing process too difficult to even bother?