They really are becoming mainstream when they say god is performing miracles for them in the form of sand !
Shows how cynical the GB is to fool the dumb sheep with this story. We are talking about making construction grade concrete for a public building are'nt we ?
Well I worked for 18 years in the concrete manufacturing industry including the actual manufacturing ,management and laboratory of concrete production ,and I can safely say that you do not use salty beach sand for construction !
As has been pointed out sea water is full of chemicals including salts which will make the concrete go hard prematurely which in turn can cause bad cracking.
Sand that is used in concrete production is washed and screened to remove impurities and the particles are graded in size carefully ,even iff the beach sand was washed to remove salts it is basically a same size grains silica sand with no fine clay type particles which basically makes a "dead" mix, even with the cement added to the mix, it won't be workable and if a concrete pump were used in the placing it would probably jam the pump from it's lack of ability to flow, and finishing the surface would be a nightmare unless lots of certain chemicals such as air entrainers were used to aerate the mix.
Not to mention ,over time, how the salts in the mix will break the cementicious bond and rust the rebar before it's time!
So iff the GB OK the use of this crappy type concrete thru their "theocratic arrangement" and Jehovahs poor judgement of sand choice ,well that just about confirms their standards in religion and building quality, and also how cynically they view the local islanders as poor dumb slobs and how that will be ok for them !
But I bet they would'nt like to use that sand to build the house they live in hoping the concrete will hold the building up - (words deleted here I have to stop that!)