Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams

Steel fiber reinforced concrete (SFRC) is a kind of multiphase composite material and its tensile strength (ft) and fracture toughness (KIC) cannot be easily measured using small samples due to its highly heterogeneous microstructure. In this study, a novel evaluation is proposed for calculating ft...

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Main Authors: Chen Yixin, Zhang Jianye, Ma Jicheng, Zhou Shunli, Liu Yongsheng, Zheng Zhixuan
Format: Article
Language:English
Published: Elsevier 2022-12-01
Series:Case Studies in Construction Materials
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2214509522005332
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author Chen Yixin
Zhang Jianye
Ma Jicheng
Zhou Shunli
Liu Yongsheng
Zheng Zhixuan
author_facet Chen Yixin
Zhang Jianye
Ma Jicheng
Zhou Shunli
Liu Yongsheng
Zheng Zhixuan
author_sort Chen Yixin
collection DOAJ
description Steel fiber reinforced concrete (SFRC) is a kind of multiphase composite material and its tensile strength (ft) and fracture toughness (KIC) cannot be easily measured using small samples due to its highly heterogeneous microstructure. In this study, a novel evaluation is proposed for calculating ft and KIC of brittle heterogeneous solids. The results obtained by this method have been confirmed by three-point bending (TPB) test results of 75 notched SFRC beams in which the length of the corrugated steel fibers is 36 mm. Considering the heterogeneity and discontinuous fracture failure characteristic of SFRC samples, a virtual crack propagation calculation model is established, and the accurate prediction of ft and KIC can be obtained by incorporating the model into the Hu-Duan boundary effect model (BEM). The reasonable range of tensile strength of SFRC used in this paper is about 3.77–5.66 MPa. Compared with the median value of this range, the calculation error of BEM is only 7.69 %. By discussing the influence of α-ratio (defined as the ratio between the height W and the initial notch depth a0) on the predicted results, a value that is less affected by the front and rear boundary is obtained, and the value range is 0.16–0.24. Meanwhile, the exact ft and KIC can be obtained by using only 1–2 groups of samples with reasonable α-ratio. Based on the failure curve of SFRC established by using ft and KIC, the theoretical minimum size of samples with different α-ratio is determined under the condition of linear elastic fracture mechanics (LEFM). This method provides a valuable reference for the estimation of concrete mechanical parameters.
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spelling doaj.art-b90160ea52a94d0db8d04e9a56615b732022-12-22T03:44:37ZengElsevierCase Studies in Construction Materials2214-50952022-12-0117e01401Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beamsChen Yixin0Zhang Jianye1Ma Jicheng2Zhou Shunli3Liu Yongsheng4Zheng Zhixuan5Key Laboratory of Road Construction Technology & Equipment, Ministry of Education, Chang’an University, Xi’an 710064, Shaanxi, ChinaKey Laboratory of Road Construction Technology & Equipment, Ministry of Education, Chang’an University, Xi’an 710064, Shaanxi, ChinaKey Laboratory of Road Construction Technology & Equipment, Ministry of Education, Chang’an University, Xi’an 710064, Shaanxi, ChinaKey Laboratory of Road Construction Technology & Equipment, Ministry of Education, Chang’an University, Xi’an 710064, Shaanxi, ChinaKey Laboratory of Road Construction Technology & Equipment, Ministry of Education, Chang’an University, Xi’an 710064, Shaanxi, China; Corresponding author.Gansu Luqiao Third Highway Engineering Co., Ltd, Lanzhou 730050, Gansu, ChinaSteel fiber reinforced concrete (SFRC) is a kind of multiphase composite material and its tensile strength (ft) and fracture toughness (KIC) cannot be easily measured using small samples due to its highly heterogeneous microstructure. In this study, a novel evaluation is proposed for calculating ft and KIC of brittle heterogeneous solids. The results obtained by this method have been confirmed by three-point bending (TPB) test results of 75 notched SFRC beams in which the length of the corrugated steel fibers is 36 mm. Considering the heterogeneity and discontinuous fracture failure characteristic of SFRC samples, a virtual crack propagation calculation model is established, and the accurate prediction of ft and KIC can be obtained by incorporating the model into the Hu-Duan boundary effect model (BEM). The reasonable range of tensile strength of SFRC used in this paper is about 3.77–5.66 MPa. Compared with the median value of this range, the calculation error of BEM is only 7.69 %. By discussing the influence of α-ratio (defined as the ratio between the height W and the initial notch depth a0) on the predicted results, a value that is less affected by the front and rear boundary is obtained, and the value range is 0.16–0.24. Meanwhile, the exact ft and KIC can be obtained by using only 1–2 groups of samples with reasonable α-ratio. Based on the failure curve of SFRC established by using ft and KIC, the theoretical minimum size of samples with different α-ratio is determined under the condition of linear elastic fracture mechanics (LEFM). This method provides a valuable reference for the estimation of concrete mechanical parameters.http://www.sciencedirect.com/science/article/pii/S2214509522005332SFRCTensile strengthFracture toughnessBoundary effect modelTPB testNotched beam
spellingShingle Chen Yixin
Zhang Jianye
Ma Jicheng
Zhou Shunli
Liu Yongsheng
Zheng Zhixuan
Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
Case Studies in Construction Materials
SFRC
Tensile strength
Fracture toughness
Boundary effect model
TPB test
Notched beam
title Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
title_full Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
title_fullStr Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
title_full_unstemmed Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
title_short Tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
title_sort tensile strength and fracture toughness of steel fiber reinforced concrete measured from small notched beams
topic SFRC
Tensile strength
Fracture toughness
Boundary effect model
TPB test
Notched beam
url http://www.sciencedirect.com/science/article/pii/S2214509522005332
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AT majicheng tensilestrengthandfracturetoughnessofsteelfiberreinforcedconcretemeasuredfromsmallnotchedbeams
AT zhoushunli tensilestrengthandfracturetoughnessofsteelfiberreinforcedconcretemeasuredfromsmallnotchedbeams
AT liuyongsheng tensilestrengthandfracturetoughnessofsteelfiberreinforcedconcretemeasuredfromsmallnotchedbeams
AT zhengzhixuan tensilestrengthandfracturetoughnessofsteelfiberreinforcedconcretemeasuredfromsmallnotchedbeams