Heated and Bent Anchor Rods
Heated and Bent Anchor Rods
(OP)
For those of you having to remedy a contractors lack of quality control, here is a question for you:
I am a new structural engineer left to research a current anchor bolt problem we are having. The contractor failed to insure the 22 inch long, 1 inch diameter anchor rods were plum before concrete hardened. The exposed 5 inches of rod were not able to accept the base plates due to their angle. Construction workers decided to torch heat the tops and bend them back straight. This not only left scortched threads on the anchor rods and a glassy concrete surface, but most likely affected both the steel and concrete pedestal's material properties. The contractor is not worried about the issue, but as engineers it is our duty to address questionable areas such as these. A load test has been requested on anchor rods having this "straightening" performed on them. The test has not yet been performed, but things are heading in that direction.
Has anyone experienced a similar problem? How are the materials properties affected by this heating and bending? Is a load test the best answer to the problem? I am not familiar with load testing, but to provide a straight tension pull it seems as though the equipment might be fairly large sized to avoid bearing on the pedestal. Any help on this matter would be helpful and greatly appreciated. Thanks.
I am a new structural engineer left to research a current anchor bolt problem we are having. The contractor failed to insure the 22 inch long, 1 inch diameter anchor rods were plum before concrete hardened. The exposed 5 inches of rod were not able to accept the base plates due to their angle. Construction workers decided to torch heat the tops and bend them back straight. This not only left scortched threads on the anchor rods and a glassy concrete surface, but most likely affected both the steel and concrete pedestal's material properties. The contractor is not worried about the issue, but as engineers it is our duty to address questionable areas such as these. A load test has been requested on anchor rods having this "straightening" performed on them. The test has not yet been performed, but things are heading in that direction.
Has anyone experienced a similar problem? How are the materials properties affected by this heating and bending? Is a load test the best answer to the problem? I am not familiar with load testing, but to provide a straight tension pull it seems as though the equipment might be fairly large sized to avoid bearing on the pedestal. Any help on this matter would be helpful and greatly appreciated. Thanks.






RE: Heated and Bent Anchor Rods
RE: Heated and Bent Anchor Rods
RE: Heated and Bent Anchor Rods
If it's a large open hangar type building, then it's possibly a pre-engineered metal building and you might want to check with the supplier/manufacturer to see what the impact on any warranty might be. They often supply the AB's. In these areas the design of many of the pre-eng buildings is pretty tight and the design loadings often have a minimal design for opening related wind pressures and the uplift forces may not be conservative.
RE: Heated and Bent Anchor Rods