Influence of fiber alignment and length on flexural properties of UHPC

Gao, Xiaojian; Gao, Xiaojian; Khayat, Kamal H.; Su, Anshuang

doi:10.1016/j.conbuildmat.2021.122863

Cited by 42 publications

(10 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This seems to indicate that the stronger interactions between longer fibers are detrimental to fiber alignment [ 51 , 65 ]. Huang et al [ 71 , 72 ] used a special L-shaped mold to cast a UHPC, and found that the long fibers were blocked at a high content, which indicates that the mutual interference between a large number of long fibers affects the flexural tensile strength. However, Abbas et al [ 41 ] found that a UHPC with short fibers (

= 8 mm) has the highest flexural strength and a smaller crack width.…”

Section: Resultsmentioning

confidence: 99%

“…In the collected papers, all the researchers have consistently believed that a hybrid of straight and deformed steel fibers does not improve the first-cracking strength [ 47 , 50 , 53 , 63 , 67 , 70 , 73 ]. Yoo et al [ 71 ] found that the improvement in the flexural tensile strength after the hybridization of medium–long straight fibers (

= 19.5 mm) and long deformed fibers (

= 30 mm) was inferior to that of a single medium–long straight fiber. Kim et al [ 47 ] found that hybrid, long deformed fibers (

≥ 30 mm) and medium–long straight fibers (

= 13 mm) improve the flexural strength, which is related to the content of the medium–long fibers.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Steel Fibers on Tensile Properties of Ultra-High-Performance Concrete: A Review

Du,

Yu,

Qiu

et al. 2024

Materials

View full text Add to dashboard Cite

Ultra-high-performance concrete (UHPC) is an advanced cement-based material with excellent mechanical properties and durability. However, with the improvement of UHPC’s compressive properties, its insufficient tensile properties have gradually attracted attention. This paper reviews the tensile properties of steel fibers in UHPC. The purpose is to summarize the existing research and to provide guidance for future research. The relevant papers were retrieved through three commonly used experimental methods for UHPC tensile properties (the direct tensile test, flexural test, and splitting test), and classified according to the content, length, type, and combination of the steel fibers. The results show that the direct tensile test can better reflect the true tensile strength of UHPC materials. The tensile properties of UHPC are not only related to the content, shape, length, and hybrids of the steel fibers, but also to the composition of the UHPC matrix, the orientation of the fibers, and the geometric dimensions of the specimen. The improvement of the tensile properties of the steel fiber combinations depends on the effectiveness of the synergy between the fibers. Additionally, digital image correlation (DIC) technology is mainly used for crack propagation in UHPC. The analysis of the post-crack phase of UHPC is facilitated. Theoretical models and empirical formulas for tensile properties can further deepen the understanding of UHPC tensile properties and provide suggestions for future research.

show abstract

= 8 mm) has the highest flexural strength and a smaller crack width.…”

Section: Resultsmentioning

confidence: 99%

= 19.5 mm) and long deformed fibers (

= 30 mm) was inferior to that of a single medium–long straight fiber. Kim et al [ 47 ] found that hybrid, long deformed fibers (

≥ 30 mm) and medium–long straight fibers (

= 13 mm) improve the flexural strength, which is related to the content of the medium–long fibers.…”

Section: Resultsmentioning

confidence: 99%

Effect of Steel Fibers on Tensile Properties of Ultra-High-Performance Concrete: A Review

Du,

Yu,

Qiu

et al. 2024

Materials

View full text Add to dashboard Cite

show abstract

“…These results indicated that the use of a hybrid mix of steel and polypropylene fibers in the prepared concrete enhances the flexural behaviors in terms of post-crack strength, toughness ability, and deflection in comparison to other prepared samples. Similarly, Huang et al [33] found that the length of the steel fibers highly affected the flexural behaviors of UHPC, with the maximum bending strength and toughness achieved with steel fibers of 20 mm in length. The authors noted that the enhancements in the bending behavior and toughness were 19% and 125%, respectively.…”

Section: Flexural Strengthmentioning

confidence: 86%

“…Usually, the production of UHPC needs a relatively high quantity of cement, and often, the required amount is not evaluated or optimized. Thus, the economic cost and environmental issues present the main challenges in the production process of UHPC [28][29][30][31][32][33]. Moreover, the use of UHPC in construction is limited due to its high cost of production.…”

Section: Introductionmentioning

confidence: 99%

Development and Performance Evaluation of UHPC and HPC Using Eco-Friendly Additions as Substitute Cementitious Materials with Low Cost

2023

View full text Add to dashboard Cite

Ultra-high-performance concrete (UHPC) and high-performance concrete (HPC) are widely used in construction engineering applications. The quality and economy of this type of concrete are the main challenges in real construction systems due to their expensive cost. In the present investigation, the performances of UHPC and HPC were improved using eco-friendly additives from natural sources or industrial wastes. Accordingly, different kinds of concrete mixtures were prepared with the addition of various eco-friendly materials, such as metakaolin (10, 15, and 20%), silica fume (2.5, 5, 10, and 15%), cement kiln dust (CKD) (0, 5, and 10%), and 1 vol.% of steel and polypropylene fibers. All of these materials were subjected to efficient treatment and purification processes. The results indicated that the prepared UHPC was characterized by high compression and flexural strengths. The prepared UHPC (sample CR-2) with metakaolin (10%), CKD (10%), and 1 vol.% of steel fibers provided the highest compressive strength of 135 MPa at 28 days. Moreover, the results showed that reducing the cement amounts to 750, 500, and 250 kg/m3 provided concrete with efficient structural requirements and specifications and can be characterized as UHPC and HPC. Also, the mixture (sample CM15) with a metakaolin addition of 15%, CKD of 100 kg/m3, and 1 vol.% of steel fibers showed the highest flexural strength of 19.14 MPa at 28 d. Moreover, the highest splitting tensile strength of the prepared UHPC cylinders was 9.6 MPa at 28 d for the MSS1000 sample, which consisted of 15% metakaolin, a cement content of 1000 kg/m3, silica fume of 10%, and steel fibers of 1% vol. The prepared UHPC mixtures will reduce the amount of consumed cement and the production cost, with a high performance in comparison to classical concrete. Finally, it was clear that the prepared UHPC and HPC concrete with green additions can serve efficiently in specific construction applications, with high performance, economic feasibility, and safe environmental impacts.

show abstract

“…For UHPC beams with low fiber contents and without any reinforcing steel, only one main crack occurred under four-point bending loading [36]. Huang and Teng [37,38] used a specific casting method to improve the fiber orientation and corresponding flexural performance of UHPC beams with 2% steel fibers and without any reinforcing steel. The results showed that there was only one main crack on UHPC with improved fiber orientation.…”

Section: 5 Calculation Of the Average Inertia Of Bending Moment Of Cracked R-uhpc Beamsmentioning

confidence: 99%

Tension-Stiffening Effect Consideration for Modeling Deflection of Cracked Reinforced UHPC Beams

2021

View full text Add to dashboard Cite

Tension-stiffening effects can significantly influence the flexural performance of cracked reinforced concrete specimens. Such effect is amplified for fiber-reinforced concrete, given the fact that fibers can bridge the cracks. The objective of this study was to develop a model to predict the deflection of cracked reinforced ultra-high performance concrete (R-UHPC) beam elements. The modeling approach characterized the average bending moment of inertia by combining the existing model used for conventional reinforced concrete and the analytical model of stress distribution of UHPC along the cross-section. The finite element analysis (FEA) was employed to evaluate the flexural deflection based on the average bending moment of inertia. The calculated load-deflection relationships have been compared to experimental results. The results indicated that the relative errors of deflection between predicted and experimental results can be controlled within 15%, compared to values ranging from 5% to 50% calculated by neglecting the tensile properties of cracked UHPC and values ranging from 5% to 30% calculated by effective inertia of bending moment of ACI code. Therefore, the developed model can be used in practice because it can secure the accuracy of deflection prediction of the R-UHPC beams. Such a simplified model also has higher sustainability compared to FEA using solid elements since it is easier and time-saving to be established and calculated.

show abstract

Influence of fiber alignment and length on flexural properties of UHPC

Cited by 42 publications

References 43 publications

Effect of Steel Fibers on Tensile Properties of Ultra-High-Performance Concrete: A Review

Effect of Steel Fibers on Tensile Properties of Ultra-High-Performance Concrete: A Review

Development and Performance Evaluation of UHPC and HPC Using Eco-Friendly Additions as Substitute Cementitious Materials with Low Cost

Tension-Stiffening Effect Consideration for Modeling Deflection of Cracked Reinforced UHPC Beams

Contact Info

Product

Resources

About