Mechanical and Surface Geometric Properties of Reinforcing Bars and Their Significance for the Development of Near-Surface Notch Stresses

Rappl, Stefan; Hameed, Muhammed Zubair Shahul; Krempaszky, Christian; Osterminski, Kai

doi:10.3390/math11081910

Cited by 5 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are in good agreement with the experimental results from Section 3 and those of Rappl et al [ 21 ]. In Section 3 , a maximum martensite area fraction of 34% was determined.…”

Section: Numerical Investigationssupporting

confidence: 92%

“…The yield stress of bainite, pearlite and ferrite is Y bpf = 431 MPa. Using the linear rule of mixture, the yield stress of the periodic unit cell is approximately These results are in good agreement with the experimental results from Section 3 and those of Rappl et al [21]. In Section 3, a maximum martensite area fraction of 34% was determined.…”

Section: Phase Distribution and Mechanical Propertiessupporting

confidence: 86%

“…The specimen used was manufactured by the same manufacturer as the first specimen examined by Volkwein et al [ 7 ]. It was from the same batch as the specimens investigated by Hameed et al [ 11 ] and Rappl et al [ 21 ].…”

Section: Experimental Investigationsmentioning

confidence: 99%

“…The thickness of the outer martensitic rim was approximately 2.5 mm, with the maximum hardness value of 292 HV. Rappl et al [ 21 ] conducted tensile tests on rebar specimens with a nominal diameter of

mm and determined the proportional limit of these specimens as

MPa. This value is in good agreement with the calculated value for the yield stress (555 MPa).…”

Section: Numerical Investigationsmentioning

confidence: 99%

See 3 more Smart Citations

Residual Stresses in Ribbed Reinforcing Bars

Robl,

Hegele,

Krempaszky

et al. 2023

Materials

Self Cite

View full text Add to dashboard Cite

Ribbed reinforcing bars (rebars) are used for the reinforcement of concrete structures. In service, they are often subjected to cyclic loading. In general, the fatigue performance of rebars may be influenced by residual stresses originating from the manufacturing process. Knowledge about residual stresses in rebars and their origin, however, is sparse. So far, residual stress measurements are limited to individual stress components, viz., to the non-ribbed part of the rebar surface. At critical points of the rebar surface, where most of the fatigue cracks originate, i.e., the foot radius regions of transverse ribs, the residual stress state has not yet been investigated experimentally. To extend the knowledge about residual stresses in rebars within the scope of this work, residual stress measurements were carried out on a rebar specimen with a diameter of 28 mm made out of the rebar steel grade B500B. In addition, numerical simulations of the TempCoreTM process were carried out. The results of the experimental investigations show tensile residual stresses in the core and the transition zone of the examined rebar specimen. Low compressive residual stresses are measured at the non-ribbed part of the rebar surface, while high compressive residual stresses are present at the tip of the transverse ribs. The results of the numerical investigations are in reasonable accordance with the experimental results. Furthermore, the numerical results indicate moderate tensile stresses occurring on the rebar surface in the rib foot radius regions of the transverse ribs. High stress gradients directly beneath the rebar surface, which are reported in the literature and which are most likely related to a thin decarburized surface layer, could be reproduced qualitatively with the numerical model developed.

show abstract

“…These results are in good agreement with the experimental results from Section 3 and those of Rappl et al [ 21 ]. In Section 3 , a maximum martensite area fraction of 34% was determined.…”

Section: Numerical Investigationssupporting

confidence: 92%

Section: Phase Distribution and Mechanical Propertiessupporting

confidence: 86%

Section: Experimental Investigationsmentioning

confidence: 99%

mm and determined the proportional limit of these specimens as

MPa. This value is in good agreement with the calculated value for the yield stress (555 MPa).…”

Section: Numerical Investigationsmentioning

confidence: 99%

See 2 more Smart Citations

Residual Stresses in Ribbed Reinforcing Bars

Robl,

Hegele,

Krempaszky

et al. 2023

Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…The plain bars consisted of a ferrite/pearlite microstructure, whereas the reinforcing steel bar possessed an outer martensite ring due to the Tempcore ® process [40]. The results were in good agreement with the literature, where ferrite/pearlite microstructures demonstrated a lower strength and a higher ductility than the martensitic microstructure [41]. The cold-formed threaded rods did not show a distinct yield strength.…”

Section: Reinforcement Characterizationsupporting

confidence: 79%

Bond Behavior of WAAM Reinforcements in Comparison to Conventional Steel Reinforcements

Tischner,

Rappl,

Riegger

et al. 2023

Construction Materials

Self Cite

View full text Add to dashboard Cite

Additive manufacturing is becoming increasingly important in the construction industry. Wire arc additive manufacturing (WAAM) can be integrated into the selective paste intrusion (SPI) to enable the simultaneous printing of reinforced concrete. The bond behavior of a WAAM reinforcement was investigated with pull-out tests and compared to alternative reinforcement types to analyze the stress transfer between the different components. In the first step, the surface of all the reinforcement types was recorded using a laser-based line scan measuring system. This permits the evaluation of the surface parameters, such as the surface roughness Rq, or the related rib area fR. The WAAM reinforcement showed a bond behavior in the pull-out tests that was comparable to a reinforcing steel bar. Both the bond stresses achieved, and the occurring scatter of the measurement results at the characteristic slip values were almost the same. Even without existing transverse ribs, the WAAM reinforcement reached maximum bond stresses similar to the reinforcing steel. An evaluation of the surface roughness revealed a linear relationship with the maximum bond stress achieved with a logarithmic scaling of Rq. The bond work Wτ, which is a measure of the system stiffness, showed that WAAM reinforcements and reinforcing steel bars have approximately similar behavior.

show abstract