INVESTIGATION OF THE ANCHORAGE BEHAVIOR OF HEADED REINFORCING BARS USING THE FINITE ELEMENT METHOD By

A headed reinforcing bar is a new type of reinforcement with a T-shaped anchor connected to the end of a reinforcing bar. Conceptually, the bar is usually a tension member or compression one depending on structural engineering applications. The T-shaped anchor, referred to as head in the rest of this report is a relatively stiff steel "plate" in terms of its structural behavior. When embedded in concrete. the head provides anchorage for the bar to which it is attached, so that the tension or compression force can be developed in the bar. Practically, in reinforced concrete structures. the reinforcing bar can be simply a deformed bar or a round steel bar. The head could be a small piece of steel "plate" in any realistic shape providing that it functions as an anchor. meets economical considerations, and fits the individual application. The head investigated in this project is a square plate shown in Fig. 1.1-1 below. The connection between the head and the bar should be strong enough so that the yield force in the bar can be developed. Therefore, the head should be forged or welded to the end of the bar. One such welding process is fiiction-welding whereby the fiiction between a bar and plate when moved relative to one another meets two together. As an alternative, the head might be screwed to the end of a bar like the relationship between a nut and the threaded end of a bolt. There are some reasons for engineers to use headed reinforcing bars instead of conventional bars in structural design and construction. First, using a headed bar uses the advantage of the effective anchorage property of the head. It is not difficult for a structural engineer to understand that one can obtain much better anchorage for his or her reinforcement design by using a headed bar than by using a bar with anchorage along its length. Even for one who is not an engineer, for example, can tell the difference between pulling a wood pile embedded in soil and dragging a tree trunk with roots underneath out of ground. Obviously, the same concept applies in the anchorage behavior of a traditional bar and a headed bar. Second, using a headed bar is simpler than using traditional deformed bar in terms of material and anchorage. The basic principle of a reinforced concrete structure is that the bar and concrete can work …