Performance of two‐to‐one non‐contact post‐installed lap splices

Post‐installed lap splices ensure the continuity of steel reinforcement in concrete‐to‐concrete connections by overlapping cast‐in (CI) reinforcing bars (rebars) with post‐installed (PI) rebars. Typically, the design of such splices follows provisions originally intended for CI lap splices, despite the differences in execution and bond performance. This study introduces a novel design concept for PI lap splices, where two CI rebars are overlapped with a centrally placed PI rebar using high‐performance injection mortar. Different slab connections with rebar diameter from 12 to 16 mm in normal‐strength concrete were tested in four‐point bending with static loading. The clear spacing between the overlapped bars varied from 4 to 8. Experimental results for the two‐to‐one non‐contact PI lap splices show similar strength, stiffness, and ductility compared to reference configurations with continuous bars as well as one‐to‐one CI and PI lap splices. The ultimate strength is always limited by the anchorage of the CI rebars within the lap splice, exceeding the predictions by the current and next‐generation Eurocode 2 design formulae.