Determining Shear Capacity of Ultra-high Performance Concrete Beams by Experiments and Comparison with Codes

Pourbaba, Masoud; Joghataie, Abdolreza

doi:10.24200/sci.2017.4264

Cited by 7 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pu et al 55 carried out shear tests on 12 RPC beams with different stirrup ratios, longitudinal reinforcement ratios and shear-span ratios, simulated the stress process of RPC beams after cracking, and analysed the factors affecting the shear capacity of RPC beams based on the softening truss mode. Pourbaba et al 56 produced 19 ultrahigh performance RC rectangular beam specimens for shear performance studies and compared the test results with those predicted by ACI 318, RILEM TC 162-TDF, Australian Guidelines and the National Building Code of Iran. Compared with the test values, the predicted shear force obtained by various codes has a safety factor of 10 times.…”

Section: Database Establishmentmentioning

confidence: 99%

Prediction of the shear capacity of ultrahigh-performance concrete beams using neural network and genetic algorithm

Hou

Hou²

2023

Sci Rep

View full text Add to dashboard Cite

Currently, concrete structures have increasingly higher requirements for the shear capacity of beams, and ultrahigh-performance concrete (UHPC) beams are increasingly widely used. To facilitate the design of UHPC beams, this paper constructs a UHPC beam shear strength prediction model. First, static shear tests were conducted on 6 UHPC beam specimens with a length of 2 m and a cross-sectional size of 200 mm × 300 mm to explore the effects of the UHPC strength, shear span ratio, hoop ratio, and steel fiber content on the shear resistance and failure morphology of the UHPC beams. Based on the results of this study and a static load experiment of 102 UHPC beams in the literature, the construction includes the shear span ratio (λ), beam section width (b), beam section height (h), hoop ratio (ρSV), UHPC compressive strength (fc), steel fiber volume fraction (Vf), and the UHPC beam shear capacity (Vex) 7 parameter database. Based on the construction of the database, 1200 BPNN models were trained through trial and error. The models were evaluated using the correlation coefficient R, root mean square error RMSE, and a20-index indicators, and the optimal BPNN model (6-15-8-1) was determined based on the ranking of RMSE. After the optimal BPNN is optimized by a genetic algorithm, the prediction performance of the model is improved. The correlation coefficient between the predicted value and the experimental value is R2 = 0.98667, and RMSE = 7.38. This model can reliably predict the shear strength of UHPC beams and provide designers with a reference for the design of UHPC beams. Finally, after sensitivity analysis, the influence of each input parameter on the UHPC shear capacity is determined.

show abstract

Section: Database Establishmentmentioning

confidence: 99%

Prediction of the shear capacity of ultrahigh-performance concrete beams using neural network and genetic algorithm

Hou

Hou²

2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…( c ) Lim et al, 2016 [ 26 ]. ( d ) Pourbaba et al, 2018 [ 34 , 35 ]. ( e ) Pansuk et al, 2017 [ 36 ].…”

Section: Figurementioning

confidence: 99%

Shear Strength of Ultra-High-Performance Concrete (UHPC) Beams without Transverse Reinforcement: Prediction Models and Test Data

Kodsy

Morcous

2022

Materials

View full text Add to dashboard Cite

The use of Ultra-High-Performance Concrete (UHPC) in beams has been growing rapidly in the past two decades due to its superior mechanical and durability properties compared to conventional concrete. One of the areas of interest to designers is the elimination of transverse reinforcement as it simplifies beam fabrication/construction and could result in smaller and lighter beams. UHPC has a relatively high post-cracking tensile strength due to the presence of steel fibers, which enhance its shear strength and eliminate the need for transverse reinforcement. In this paper, UHPC shear test data were collected from the literature to study the effect of the following parameters on the shear strength of UHPC beams without transverse reinforcement: compressive strength, tensile strength, level of prestressing, longitudinal reinforcement ratio, and fiber volume fraction. Statistical analysis of test data indicated that level of prestressing and tensile strength are the most significant parameters for prestressed UHPC beams, whereas longitudinal reinforcement ratio and tensile strength are the most significant parameters for non-prestressed UHPC beams. Additionally, shear strength of the tested UHPC beams was predicted using five models: RILEM TC 162-TDF, 2003, fib Model Code, 2010, French Standard NF P 18-710, 2016, PCI-UHPC Structures Design Guide, 2021, and Draft of AASHTO Guide Specification for Structural Design with UHPC, 2021. Comparing measured against predicted shear strength indicated that the French Standard model provides the closest prediction with the least scatter, where the average measured-to-predicted strength was 1.1 with a standard deviation of 0.38. The Draft of AASHTO provided the second closest prediction where the average measured-to-predicted strength was 1.3 with a standard deviation of 0.64. The other three models underestimated the shear strength.

show abstract

“…Even in conventional reinforced concrete structures, the shear behavior still poses many unresolved issues [30]. Despite this, the majority of the shear strength calculation approaches and models for UHPC members are empirical formulas that stem from experimental results and mathematical formulas, lacking explicit physical meaning [31]. Furthermore, the current research rarely focuses on the shear bearing capacity calculation of UHPC beams, and the shear theories of conventional RC are not suitable for UHPC beams [32,33].…”

Section: Introductionmentioning

confidence: 99%

Shear Strength of Ultra-High-Performance Concrete Beams without Stirrups—A Review Based on a Database

Huang,

Yao

2024

Buildings

View full text Add to dashboard Cite

This paper presents a comprehensive study on ultra-high-performance concrete (UHPC) beams without stirrups, where the test data of 487 beams were collected, and an experimental database was established. Four distinct shear strength calculation models for UHPC beams were examined in the study. These models were created from national specification guides. The results indicate that while the code equation is useful for predicting UHPC beam shear capacity, it consistently underestimates actual values, with a mean experimental-to-calculated ratio above 1.5. The database was also used to study the impacts of the compressive strength of UHPC, the shear span-to-depth ratio, the fiber volume fraction, and the reinforcement ratio on the shear strength of UHPC beams. The findings showed that the shear span-to-depth ratio significantly affected the shear load-bearing capacity of UHPC beams. The increase in the compressive strength of UHPC, fiber volume fraction, and reinforcement ratio positively affected the shear strength of UHPC beams to varying degrees. Additionally, there were size effects for beams with a shear span-to-depth ratio of less than 1.5 and an effective depth of more than 300. In addition, coefficients accounting for fiber influence and the shear span-to-depth ratio were incorporated to develop an enhanced formula for UHPC beams. The empirical data from the database tests revealed that the average ratio of the beams’ experimental shear capacity to the values predicted by the modified equation is 1.3, with a standard deviation of 0.74. These results suggest that the refined equation offers improved calculation precision and broader applicability. Eventually, a summary of the issues pertaining to the shear performance of UHPC beams and the key future research directions is provided to facilitate a clearer comprehension and awareness of emerging concepts for scholars within the discipline.

show abstract

Determining Shear Capacity of Ultra-high Performance Concrete Beams by Experiments and Comparison with Codes

Cited by 7 publications

References 6 publications

Prediction of the shear capacity of ultrahigh-performance concrete beams using neural network and genetic algorithm

Prediction of the shear capacity of ultrahigh-performance concrete beams using neural network and genetic algorithm

Shear Strength of Ultra-High-Performance Concrete (UHPC) Beams without Transverse Reinforcement: Prediction Models and Test Data

Shear Strength of Ultra-High-Performance Concrete Beams without Stirrups—A Review Based on a Database

Contact Info

Product

Resources

About