Shear carrying capacity of Ultra-High Performance Concrete beams

Hegger, Josef; Bertram, Guido

doi:10.1201/9781439828410.ch59

Cited by 23 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, the negligible change in the bond strength obtained in this study might be due to the small differences between the prestressing forces, which were too small to provide any significant changes for the strands embedded in UHPFRC. In addition, to achieve the significant Hoyer effect required to improve the bond strength of the prestressing strands, a sufficient embedment length is required to transfer strand stress to the surrounding concrete (Hegger et al 2004). However, in this study, extremely short embedment lengths of 1d b and 2d b that resulted in a limited Hoyer effect were applied.…”

Section: Effect Of Initial Prestressing Forcementioning

confidence: 99%

“…For example, the average bond strengths of round steel bars in UHPFRC were found to be 7.0, 6.2, and 5.4 MPa for the cases of 1d b , 1.5d b , and 2d b , respectively. Owing to their deformed shape, which was due to 7-wire twisting and a Hoyer effect at the live end (Hegger et al 2004), the strands achieved much higher bond strengths than the round steel bars. The diameter of the strand was initially reduced by Poisson's effect when a pretensioning was applied (before cutting the strand).…”

Section: Transfer Lengthmentioning

confidence: 99%

See 1 more Smart Citation

Bond Behavior of Pretensioned Strand Embedded in Ultra-High-Performance Fiber-Reinforced Concrete

Shin

Lee

Yoo

2018

Int J Concr Struct Mater

View full text Add to dashboard Cite

This study aimed to investigate the bond properties of prestressing strands embedded in ultra-high-performance fiberreinforced concrete (UHPFRC). Toward this end, two types of prestressing strands with diameters of 12.7 and 15.2 mm were considered, along with various concrete cover depths and initial prestressing force magnitudes. The average bond strength of the strands in UHPFRC was estimated by using pullout tests, and the transfer length was evaluated based on a 95% average maximum strain method. Test results indicated that the average bond strength of the pretensioned strand reduced as the diameter of the strand increased, and was between the bond strengths of round and deformed steel rebars. Higher bond strength was also obtained with a lower embedment length. Based on a comparison of p value, the bar diameter and embedment length most significantly influenced the bond strength of strands in UHPFRC, compared to a ratio of cover depth to diameter and initial prestressing force. Pretensioned strands in UHPFRC exhibited much higher bond strength and shorter transfer length compared with strands embedded in ordinary high-strength concrete. Lastly, ACI 318 and AASHTO LRFD codes significantly overestimated the transfer length of the strands embedded in UHPFRC.

show abstract

Section: Effect Of Initial Prestressing Forcementioning

confidence: 99%

Section: Transfer Lengthmentioning

confidence: 99%

Bond Behavior of Pretensioned Strand Embedded in Ultra-High-Performance Fiber-Reinforced Concrete

Shin

Lee

Yoo

2018

Int J Concr Struct Mater

View full text Add to dashboard Cite

show abstract

“…Das Sprengwerk, auch Druckbogen genannt, verläuft unmittelbar ins Auflager und muss dort mit der eingeleiteten Vorspannkraft im Gleichgewicht stehen [16]. Ist die Übertragungslänge der Litze größer als der Auflagerüberstand, unterstützt lediglich der über dem Auflager übertragene Anteil der Vorspannung das Sprengwerk [11], [12].…”

Section: Tragverhalten Und Bemessungunclassified

Innovative Konzepte im Massivbau

Hegger

Bertram

Dreßen

et al. 2009

Beton und Stahlbetonbau

Self Cite

View full text Add to dashboard Cite

show abstract

“…Für eine sichere und wirtschaftliche Bemessung ist ein auf UHPC abgestimmtes Verbundmodell erforderlich, das die spezifischen Einflüsse der Faserwirkung und der Betondeckung auf die Übertragungslänge erfasst. Die sichere Einleitung und Verankerung der Vorspannkraft ist für die Querkrafttragfähigkeit sowohl von Spannbetonbalken [4] als auch von Spannbetonhohlplatten [5,6] von entscheidender Bedeutung.…”

Section: Introductionunclassified