Lapped joints with smooth and deformed bars
New reinforced-concrete members in existing structures
In building on existing structures, reinforced-concrete members are frequently placed against existing structural members. This is best achieved with lapped joints.
Until the end of the 1950s, primarily smooth bars, as a rule, bars with low yield strength, were used. The deformed bars, which were introduced under a national technical approval in the 1950s, were regulated in the relevant design code DIN 1045 only since 1972. While historic lapping of smooth bars was possible only with end hooks and additional restrictions on impact contributions and steel stresses, lapping of single-layer...
