Moisture accumulation and freeze-thaw action only made the problem worse, and didn't necessarily cause the initial cracking. Other forces are at work, as I referenced earlier. And, no, just allowing things to remain "as is" is not a practical remedy. Freeze-thaw damage always becomes more pronounced when dirt works its way into a crack, which tends to hold onto moisture and enabling it to expand in volume (and displace things) when frozen. The spalled corner will continue to displace, to the point of completely breaking free. At that point, a proper repair becomes more complicated, and definitely requires more of an effort, if done correctly.
Going on half a century, I've monitored and administered (under DOT and private consultant contracts) concrete repairs of several hundred structures, costing hundreds of thousands of dollars, that often started with shallow, "non-structural" cracks that no one ever thought were serious enough to do anything about. The photo in my avatar is one such structure, which will likely cost its owner several million $$$ to either properly repair or completely replace.
Last edited by BridgeMan; 02-10-2012 at 11:10 PM.