Effect of composition variations on bond properties of Self-Compacting Concrete specimens

Self-Compacting Concrete (SCC) has been distinguished as a promising replacement of Normally Vibrated Concrete (NVC). Since current literature has already provided sufficient data to give confidence in SCC bond behavior, further analysis should focus on confirmational or more specific analysis. The impact of water-to-binder ratio variations and different silica fume levels of cement replacement on SCC bond has been the incentive of the present study. Pull-out tests in cube specimens have been conducted for 11 SCC and 4 NVC mixtures. Various bond stresses have been evaluated. The composition changes seem be better reflected on lower bond stresses, which decrease linearly for higher water content and higher silica fume replacement levels. SCC develops an improved bond capacity compared to same strength NVC with similar composition.

► SCC bond is in general higher than or equal to NVC for lower bond stresses.
► SCC bond is improved compared to same strength NVC with similar composition.
► Lower bond stresses seem to be affected by changes in composition properties.
► Lower bond stresses decrease linearly for higher w/b ratios or silica fume levels.
► Superplasticizer-to-water ratio is a convenient parameter for bond evaluation.