its true, that sometimes it wont. but ive seen some of the best designed situations crack.and some of the worst situations not crack. sometimes all the planning in the world will leave you scratching your head...lol. large slabs are very susceptible to cracks. a bridge is a little different since youre dealing with footing, massive reinforcement and all around thicker sections most likely. im just saying dont 'count' on it not too crack or you might be very upset. sometimes all you can do aint enough when youre at the mercy of the concrete plant. they do send out crap mixes sometimes. the bad thing is they sent it to me once on my OWN floor. that cracked before i could even get done finishing it and it was in early march and no where near too hot.lol
