Solids are all within one order of magnitude of being Tons per cubic metre, kg per litre or grams per cc.

Less than one floats, more than 1 sinks. 

Fresh air has about ten times the spacing between the atoms as a solid so is about 1000 times lighter, say 1kg per cubic metre at sea level.

Have folk no automatic feel for the scale of the universe they inhabit? You'd not try to live on 3 calories or 3 million calories a day, or would you ?

If some thing that elementary that is wrong, I would suspect rigour of  the rest of it as well.

The basic conclusion, that reasonably strong paste moulded blocks can be made from crushed bricks and crushed ceramic tiles,  and that once dried they do not burn or fall apart at temperature is not exactly a surprise. The cost of making the paste and moulding it into useful shapes for building use however is not addressed.

Mike.

Solids are all within one order of magnitude of being Tons per cubic metre, kg per litre or grams per cc.

Less than one floats, more than 1 sinks. 

Fresh air has about ten times the spacing between the atoms as a solid so is about 1000 times lighter, say 1kg per cubic metre at sea level.

Have folk no automatic feel for the scale of the universe they inhabit? You'd not try to live on 3 calories or 3 million calories a day, or would you ?

If some thing that elementary that is wrong, I would suspect rigour of  the rest of it as well.

The basic conclusion, that reasonably strong paste moulded blocks can be made from crushed bricks and crushed ceramic tiles,  and that once dried they do not burn or fall apart at temperature is not exactly a surprise. The cost of making the paste and moulding it into useful shapes for building use however is not addressed.

Mike.

My apologies, Of course one cubic metre of water weighs one metric ton. 1,000 kg.    

SI units! Distance is the metre. Mass is the kilogram. So the SI unit for density is kilograms per cubic metre. Less than 1 000 floats. More than 1 000 sinks. I once had a hydrometer for testing car battery charge. Though many years ago it was calibrated in SI units, e.g. 1 270. There does seem to be some fascination with the idea that that very common substance, water, has a density of one, and various common units provide that value. But that is the beauty of the metric system - units are easily scalable.