Flexural fatigue strains of constituent materials in strengthened RC beams with UHPC strips

•Comprehensive strain data of constituent materials in strengthened RC beams.•Flexural and fatigue response of strengthened beams were confirmed with strain data.•SEM analysis to assess the integrity of bond between the parent and repair concrete.•Numerically validated the strain response of strengthened beams using FE analysis. This paper presents the comprehensive experimental studies to obtain the strain responses of constituent material in the strengthened RC beams with UHPC strips. The experiments involved static and fatigue tests on 20 beams in each beam category to predict the strain response of strengthened beams with 5, 10 and 15 mm thick UHPC strips. From the experimental results, the strain in main reinforcement was significantly reduced in beams with 10 and 15 mm thick UHPC strip comparatively, which exhibited the improved fatigue responses. Micro analytical and numerical simulations were carried out to predict or confirm the experimental observations.