Title: Experimental investigation of shear-critical prestressed steel fibre reinforced concrete beams

Author(s): De Smedt, M.; De Wilder, K.; Anastasopoulos, D.; Reynders, E. ; De Roeck, G.; Vandewalle, L.

Publication: Symposium Paper

Volume: 343

Issue:

Appears on pages(s): 121-131

Keywords: Shear, prestressed steel fibre reinforced concrete, experimental mechanics, analytical models, advanced optical measurement techniques

DOI:

Date: 10/1/2020

Abstract:
This paper presents the experimental results of prestressed steel fibre reinforced concrete (SFRC) beams and it compares analytical model predictions with these results. Six beams were subjected to a force-controlled four-point bending test until failure. The three investigated parameters were the fibre dosage, the amount of prestressing force and the presence of shear reinforcement. During the test, failure mode and load, as well as deformations, displacements and cracking pattern properties were observed by means of conventional measurement devices and advanced optical techniques, including Bragg grated optical fibres and digital image correlation technique. Additionally, material properties were determined according to standardized European tests. The experimental results were compared to analytical predictions according to shear design equations in Model Code 2010. For the six beams, an average experimental-to-predicted failure load ratio of 1.43 was found with a coefficient of variation of 7.2%. Furthermore, four other analytical models for shear design of SFRC are investigated, namely DRAMIX Guideline, RILEM TC 162-TDF sigmaepsilon method, CNR-DT 204/2006 model and a model proposed by Soetens. All models underestimate the shear capacity of prestressed SFRC beams. The underestimation increases for a higher prestress level, whereas the correlation with the fibre dosage varies within the models.