The force transfer between concrete and reinforcement depends on the bond characteristics between the two materials. Bond influences crack widths and the deflections of RC members and also determines anchorage and splice lengths. Self-compacting concrete (SCC) is characterized by a smaller amount of coarse aggregates when compared to conventional vibrated concrete. To investigate whether this change in mix design has a significant influence on the bond behaviour, a series of beam tests (according to RILEM recommendation RC6) was performed. A total of 36 specimens were cast using 3 different concrete types: one conventional vibrated concrete (CVC) and two powder-type SCC's. The bond stress-slip behaviour of reinforcing bars with diameters ranging from 12 to 40 mm has been recorded. From these tests, it can be concluded that the bond strength of SCC is even higher than it is for CVC for small bar diameters, but the difference becomes smaller for larger bar diameters

Corrosion of the steel reinforcement is among the main causes of deterioration in concrete structures. Measures of corrosion levels are typically used to evaluate the subsequent reduction in steel-to-concrete bond, but results lack accuracy. In this study, a new assessment approach based on surface cracks was investigated. Specimens were subjected to accelerated corrosion using an impressed current. With a novel sealing method, mass losses were decoupled from concrete cracking. The results indicate that surface crack widths can be better indicators of bond degradation than corrosion levels. The findings can lead to more accurate assessments and reduced maintenance costs of infrastructure.

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Knowledge of the stress-strain relationship of concrete under uniaxial compression is crucial for the design of concrete members. This study focuses on the stress-strain behaviour under compression and especially the strain-softening of self-compacting concretes produced with limestone fillers. Four self-compacting concretes (SCC) and three conventional vibrated concretes (VC) were used to produce cylindrical test specimens with an h/d ratio of 3. The σ-ε diagram at five different ages (3-91 days) was recorded during uniaxial compressive tests. The peak strain of the SCC cylinders was shown to be higher than the ones recorded for VC concretes. However, the specific toughness of both concrete types turned out to be comparable.A total of seven concrete types were tested at different ages to compare VC with SCC. The main parameters were the compressive strength, the cement type and the addi- Articles