Stockhog and Airy's. You guys came up with a million questions and got a lot of answers. But let me lend some advice from someone with 15 years of experience in dealing with large scale military projects:
Ask more questions that relate to the original question. Don't stop at two or three... dig deep and and get silly with it. Don't get side tracked until you get every single answer you are looking for even if the answers don't come from the same source. piece it all together. Where, when, why, who... who.. who... when when when. How was the concrete aquired and through who? Multiple sources, okay name them. Time lines... how long did all this take. Where is the concrete coming from? What projects is it being considered for? Is there any documentation of the concrete? Could portions of that documentation be disclosed or made public?
You said that visiting the tax office wouldn't be worth it... why not? Would it show what taxes SLJB has paid? I sure as hell would like to know what kind of taxes SLJB has paid.
Okay, it all really doesn't matter because at this point SLJB can just say that they won't give information because they are afraid of what the crazy penny investors will do.. i.e phonecalls and w/e else.
Just an outsider looking in... doesn't really seem like the questions went deep enough. I could be wrong. Take it for what it's worth. No one is perfect...