A Short Guide To High Strength Bolting

Every structure which has collapsed was declared by someone building it that it is stronger than it will ever need to be. It is easy for people to forget that the construction codes were written in blood. While it may seem a simple matter to put a bolt in a hole, getting a bolted joint to perform as designed can be an involved process. Experience shows that what is not understood is considered unimportant. The best designs are rendered meaningless if not followed as the engineer intends. The difference between intent and execution can be huge. Though there are many writings of a "how to" nature telling of the steps to follow when working with high strength bolts, and many engineering manuals for designing bolted joints, besides the AISC stuff, there is much less out there written for the contractors and inspectors which explains why those procedures are necessary. This book was written to provide the perspective and understanding necessary for contractors and inspectors to follow the design intentions avoid the common mistakes. This book gives insight into the less visible effects taking place in a bolted joint. One common error is the belief that a looser bolt is less likely to break than a tighter bolt. Through understanding the stress-strain curve for a bolt, one can learn why mistakes such as that is so dangerous, and why the full pretension specified in the RCSC Specification is there to protect the bolt, the joint and the structure from failure. Another common error is the belief that verification that the procedures are being followed is not required at every stage of bolted construction. Through and understanding of that stress-strain curve, one can also gain understanding into why certain tensioning methods are more reliable than others. With effects which are less visible to the eye, or even invisible, it is critical to understand and follow the specified procedures exactly. The world doesn't need any more examples of failure. The biggest failure is on the part of inspectors. If they did their job then the contractors would do their job. I expect some people to be offended by these facts, but facts must be spoken before meaningful change can happen. Truth may seem ugly so some, but it is only an expression of what is happening in the steel construction industry.