Over the years, many structural engineers, architects and specifiers have noted that lap splicing has few advantages and many disadvantages. Lap splices are not considered reliable under conditions of cyclic loading into the elastic range. Further, there is a question as to the effectiveness of laps with larger bars: These are major structural elements in the frame of a reinforced concrete structure, and any question regarding their efficacy is cause for concern. Over the years, to counter these concerns, the required lap lengths in the Building Code have become longer and longer. Concerns about lap splicing go to the very principles that are the basis for lap splicing. Lap splicing requires concrete to take tension and shear loads, though concrete is notoriously poor in handling tension and shear. To design a correctly engineered lap splice, certain parameters must be considered. These include:

Additional transverse reinforcement is necessary for larger bar sizes. In the area of overlap connections (lap zone), a double number of bars are present which increases rebar congestion and can restrict the flow and proper distribution of larger aggregates, causing difficulties in the efficient vibration of the concrete. This “strainer effect” is one of the major causes for forming rock pockets and contributes to poor quality concrete. Because lap splices develop their strength from concrete cover, deterioration of concrete will inevitably lead to splice failure. One disadvantage of lap splices is that they offer poor cyclic performance in the inelastic range. Without proper cover the lap splice becomes ineffective and the load path gets broken. Laps double the steel/concrete ratio and create problems while placing the bar and during concrete consolidation. Elimination of laps also frees space for post tensioning operations