Modelling the tension stiffening effect in SFR-RC

Comparing experimental results of the shear capacity of steel fiber-reinforced concrete (SFRC) beams without stirrups to the capacity predicted using current design equations and other available formulations shows that predicting the shear capacity of SFRC beams without mild steel shear reinforcement is still difficult. The reason for this difficulty is the complex mechanics of the problem, where the steel fibers affect the different shear-carrying mechanisms. Since this problem is still not fully understood, we propose the use of artificial intelligence (AI) to derive an expression based on the available experimental data. We used a database of 430 datapoints obtained from the literature. The outcome is an artificial neural network-based expression to predict the shear capacity of SFRC beams without shear reinforcement. For this purpose, many thousands of artificial neural network (ANN) models were generated, based on 475 distinct combinations of 15 typical ANN features. The proposed “optimal” model results in maximum and mean relative errors of 0.0% for the 430 datapoints. The proposed model results in a better prediction (mean Vtest/VANN = 1.00 with a coefficient of variation 1 × 10−15) as compared to the existing code expressions and other available empirical expressions, with the model by Kwak et al. giving a mean value of Vtest/Vpred = 1.01 and a coefficient of variation of 27%. Until mechanics-based models are available for predicting the shear capacity of SFRC beams without shear reinforcement, the proposed model thus offers an attractive solution for estimating the shear capacity of SFRC beams without shear reinforcement. With this approach, designers who may be reluctant to use SFRC because of the large uncertainties and poor predictions of experiments, may feel more confident using the material for structural design.

show abstract

“…The type of fibers that are used, are most often steel fibers. These fibers help to distribute cracks and keep the crack widths small [1].…”

Section: Introductionmentioning

confidence: 99%

ANN-Based Shear Capacity of Steel Fiber-Reinforced Concrete Beams without Stirrups

Abambres

Lantsoght

2019

Fibers

View full text Add to dashboard Cite

show abstract

“…If a sufficient dosage of fibers is added to the concrete mix, this may transform the failure mode of a potentially shear‐critical member from a brittle shear failure to a ductile flexural failure . This phenomenon of providing some stiffness across a crack also leads to various auxiliary practical benefits, such as the ability of the fibers to control concrete cover spalling, the reduction of curvatures/deflections, and reductions in crack widths and spacings …”

Section: Introductionmentioning

confidence: 99%

Strength of steel fiber reinforced concrete beams in pure torsion

Amin

Bentz

2018

Structural Concrete

Self Cite

View full text Add to dashboard Cite

This paper presents a simple yet accurate technique for determining the strength of steel fiber reinforced concrete beams loaded in pure torsion. The results of the model are compared with 21 beams found in the literature as well as two new beams tested by the authors and reported herein. The model considers the beneficial effect of the fibers in resisting tension after the concrete matrix has cracked, and it is implemented into the widely accepted space truss analogy for reinforced concrete members subjected to pure torsion. The proposed model provides good correlations to the collected test data with a test to predicted ratio of 1.10 and COV of 0.19. A simplified method of the aforementioned model, suitable for design, is also presented and is shown to provide good predictions to the test data.concrete, simplified MCFT, space truss analogy, steel fiber, torsion

show abstract

“…This method was unsuitable for specimens with large section sizes due to low fraction capacity. Amin et al [ 14 ] used a large section size for SFRC tensile ties with screw‐type reinforcing bars at Ø20 and Ø28 mm. The screwed reinforcement was directly connected to the universal joint machine.…”

Section: Test Methodologymentioning

confidence: 99%

Experimental methodology on the serviceability behaviour of reinforced ultra‐high performance fibre reinforced concrete tensile elements

Khorami

Navarro‐Gregori

Serna

2020

Strain

View full text Add to dashboard Cite

Design codes include serviceability limit state (SLS) provisions for stress, crack, and deflection control in concrete structures, which may limit the structural design. When drawing on reinforced ultra‐high performance fibre‐reinforced concrete (R‐UHPFRC), the process of cracking differs significantly from traditional concretes. Thus, it remains unclear whether the traditional provisions are applicable to R‐UHPFRC or should be reviewed. Uniaxial tensile tie test is an excellent option to analyse and review these criteria. This work proposes a novel test methodology to study the behaviour of R‐UHPFRC under serviceability conditions, which lets the study of the global and local deformation behaviour by using different measurement equipment. Two different types of R‐UHPFRC ties with variant fibre content were tested. The global average tensile stress–strain curve, cracking behaviour, number, and width of cracks were obtained. Promising preliminary results admitted that this methodology can be useful to propose design criteria of R‐UHPFRC under SLS.

show abstract

Modelling the tension stiffening effect in SFR-RC

Cited by 42 publications

References 10 publications

ANN-Based Shear Capacity of Steel Fiber-Reinforced Concrete Beams without Stirrups

ANN-Based Shear Capacity of Steel Fiber-Reinforced Concrete Beams without Stirrups

Strength of steel fiber reinforced concrete beams in pure torsion

Experimental methodology on the serviceability behaviour of reinforced ultra‐high performance fibre reinforced concrete tensile elements

Contact Info

Product

Resources

About