Garage concrete caused concern By Jennifer Moroz and Amy S. Rosenberg
But more than a year earlier, Atlantic City building inspectors had raised concerns with project contractors about batches of concrete that repeatedly failed in tests to reach desired strength within the standard 28 days.
In addition, city records show instances of the concrete's slump - another measure of its strength - being out of range.
Instead of changing the concrete mix, contractors and project engineers extended the test period to 90 days - an allowable practice, city officials said, but one that two independent civil engineers described yesterday as troubling.
As recently as one month before the collapse, some batches of concrete were still more than 500 pounds per square inch short of the desired strength even after 90 days, city records show.