Performance of R.C. slabs with lap splices using headed bars

This paper presents an experimental investigation on the behavior and strength of reinforced concrete slabs with lap splice of tension reinforcement using headed bars. Nine simply supported reinforced concrete one-way slabs were tested to study the effect of lap splices length, confinement at the splice zone, debonding of bars in the splice zone, and applying repeated gradually increasing cyclic loading. It was concluded that implementation of lap splice length as stated by ACI 318-14 for headed bars, but without adding confinement in the splice zone, and using cut-off ratio equal to 100%, led to brittle failure of the slab and the ductility was reduced. When the tested slabs were provided with confinement in the splice zone, the strength of slabs was improved and ductility of these slabs was remarkably increased. Additionally, the integrity of the lap joint was preserved when subjected to repeated gradually increasing cyclic loading.